Airlaid composite sheet material

ABSTRACT

Provided is a composite sheet that is particularly useful as an AQDL component in absorbent articles. The composite sheet includes a fluid acquisition component and an airlaid component. The airlaid component may include one or more airlaid layers that are successively formed overlying each other. Each of the airlaid layers are adjacent to, and in direct contact with, immediately adjacent layers of the airlaid component so that adjacent layers are in fluid communication with respect to each other. The fluid acquisition component includes a nonwoven fabric comprising a carded nonwoven fabric comprised of a plurality of staple fibers that are air through bonded to each other to form a coherent nonwoven fabric. The airlaid layer(s) include a blend of cellulose and non-cellulose staple fibers. The staple fibers may be bicomponent fibers having a polyethyelene sheath and a polypropylene or polyethylene terephthalate core, and mixtures of such fibers.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. application Ser. No.16/606,103, filed Oct. 17, 2019, which claims the benefit ofInternational Application No. PCT/IB2017/056511, filed Oct. 19, 2017,which claims the benefit of Chinese Application No. 2017 10284171.5,filed Apr. 26, 2017, the contents of which are all hereby incorporatedby reference.

FIELD

The present invention relates generally to a composite sheet materialfor use in absorbent articles, and more particularly, to a compositesheet material comprising a porous fluid acquisition layer and anairlaid layer comprising a blend of cellulose staple fiber andnon-cellulose staple fibers.

BACKGROUND

Nonwoven composite sheets made with a combination of various naturalfibers and synthetic fibers are known for use in the manufacture ofabsorbent articles. Such absorbent articles may include disposablehygiene products, such as diapers, women sanitary products, adultincontinent products, and the like.

Typical absorbent articles typically include a multilayer constructionhaving an inner layer (also referred to as a top sheet) defining aninner surface that is in contact with the skin of the wearer, anacquisition/distribution layer (also referred to as an AQDL component)disposed underlying the top sheet, an absorbent layer comprising amaterial selected to absorb fluids, and an outer layer (also referred toas a back sheet) defining an outer surface of the article. Typically,the back sheet comprises a material that is impervious to fluids so thatany fluids absorbed within the absorbent core do not escape or leak.

Materials typically used in the AQDL are typically selected to rapidlytransport fluids from the top sheet and into the absorbent core. Thisrapid transport (also referred to herein as flash permeation) transportsthe fluid in the z-direction from the top sheet to the absorbent core.In order to prevent fluid from pooling or remaining near the skin of thewearer, it is important that the distribution layer prevents or reducesreverse osmosis of fluids from the absorbent core and back through thetop sheet.

In general, many conventional materials used in the production of AQDLshave rapid fluid acquisition in the z-direction, but have undesirablelateral fluid distribution (x-direction and y-direction). As a result,fluids are quickly transported from the top sheet to the absorbent core,but are often not sufficiently distributed throughout the AQDL prior tobeing introduced into the absorbent core. This may cause the fluids tobe localized in one region of the absorbent core, and result inprolonged exposure of the skin of the wearer to the fluid. Prolongedexposure to fluids is undesirable.

SUMMARY

Embodiments of the present invention are directed to a composite sheetthat is particularly useful as a fluid AQDL component in absorbentarticles. In one embodiment, a composite sheet is provided in which thecomposite sheet comprises a fluid acquisition component and an airlaidcomponent overlying the fluid acquisition component. The airlaidcomponent may comprise one or more airlaid layers that are successivelyformed overlying each other. Preferably, each of the airlaid layers areadjacent to, and in direct contact with, immediately adjacent layers ofthe airlaid component so that adjacent layers are in fluid communicationwith respect to each other.

In one embodiment, the fluid acquisition component comprises a nonwovenfabric comprising a carded nonwoven fabric comprised of a plurality ofstaple fibers that are air through bonded to each other to form acoherent nonwoven fabric. In one embodiment, the non-cellulose fiberscomprise polymers derived from synthetic sources, and/or polymersderived from natural or sustainable sources, such as PLA. Preferredstaple fibers for the carded nonwoven fabric comprise bicomponent fibershaving a polyethyelene sheath and a polypropylene or polyethyleneterephthalate core, and mixtures of such fibers.

In one embodiment, the airlaid component comprises at least one airlaidnonwoven layer comprising a homogenous mixture of cellulose andnon-cellulose staple fibers that are deposited directly onto the surfaceof the fluid acquisition layer, or deposited directly onto a surface ofa previously deposited airlaid layer. Advantageously, the air-layer maybe thermally bonded to the fluid acquisition layer without the use ofadditional adhesives or the use of additional polymer powders andresins. Preferred non-cellulose staple fibers comprise bicomponentfibers having a polyethyelene sheath and a polypropylene or polyethyleneterephthalate core, and mixtures of such fibers.

The cellulose staple fibers may comprise treated or untreated wood pulp.The non-cellulose staple fibers may comprise bicomponent ormonocomponent fibers, or blends thereof. In one embodiment, thenon-cellulose fibers comprise polymers derived from synthetic sources,and/or polymers derived from natural or sustainable sources, such asPLA.

In comparison with prior art materials, composite sheets in accordancewith embodiments of the present invention may provide the advantagesdetailed below.

(1) The composite sheet material comprises nonwoven fabrics having goodfluid flash-permeation and distribution properties. In certainembodiments, the composite sheet material comprises a fluid acquisitionlayer that can be thermally bonded with an airlaid component while stillbeing capable of being used in subsequent conversion processes in themanufacture of absorbent articles.

(2) The composite sheet comprises an airlaid component comprising one ormore airlaid layers may also provide an absorbent article that is morecomfortable to a wearer of the absorbent article. For example, theairlaid component may comprise material that have a fluffy and softfeeling as well as low integral density. In addition, the materials forthe fluid acquisition layer and the airlaid component may be selected toprovide density gradient (e.g. lower to higher density in eachsuccessive layer) to assist in transporting a fluid quickly from the topsheet to the absorbent core.

(3) The fluid acquisition layer of the composite sheet may comprise amulti-pore structure having large average pore sizes and a relativelylow density. As a result, the fluid acquisition layer may be capable ofefficiently transporting a fluid from the top sheet, and into theairlaid component of the composite sheet.

(4) In some embodiments, the airlaid component comprises a relativelymore compact structure having a smaller pore volume, and relativelyhigher densities. In addition, the airlaid component comprises cellulosefibers, which also helps to provide fluid absorption properties. Thecombination of these properties, helps to distribute a fluid quickly andbroadly through-out the airlaid component, and to temporarily storefluid. This helps to efficiently transport and distribute the fluidthrough the airlaid layer prior to the fluid being transported into theabsorbent core

(5) The composite sheet material may also provide improved comfort tothe wearer. In particular, embodiments of the composite sheet materialmay have good rebound resiliency in comparison to other materials usedin absorbent articles. In particular, rebound resiliency measures thematerials ability to return towards its original thickness after beingsubjected to a compression force. A higher rebound resiliency isindicative of the material's overall cushiony softness and comfort. Insome embodiments, the thickness rebound resilience of articles inaccordance with embodiments of the present invention after three monthsof aging under compression may be about 15 to 60% or more. Incomparison, prior art materials, may have a rebound resilience that is10% or less. This advantage may help enable the end product absorbentarticle to have a cushiony soft and fluffy feeling to the wearer.

(6) The composite sheet may also have very good anti-reverse osmosisperformance, which results in the absorbent article having a dry-touch,and further improves the comfort of use by the wearer.

(7) The process of preparing the composite sheet also allows two kindsof fibers in the fiber layer to be homogeneously mixed and bonded toeach other and to adjacent layers of the composite sheet. This mayfurther improve the fluid distribution between layers, and through thecomposite sheet as whole. As a result, improved fluid distribution,diffusion, and absorption, resiliency, and anti-reverse osmosisproperties may be obtained in the absorbent article.

(8) As noted previously, the composite sheet may also comprise amaterial having a density gradient when absorbing a fluid. As a result,the surface stain size of the composite sheet may be smaller, and as aresult, an absorbed fluid can spread quickly when transporting throughthe fluid acquisition layer. This may help articles comprising theabsorbent article to achieve small surface stain size when absorbing afluid. The relatively larger liquid absorbing area in the airlaidcomponent, helps the absorbent articles (e.g., sanitary napkins) to havemuch smaller surface visual effect, which may also help to provide thegood reverse osmosis performance of the composite sheet.

(9) Finally, the distribution and flash-permeation of the compositesheet is improved in comparison to other materials, the anti-reverseosmosis effect is good, and as a powder binding agent and additionalpolymer resins beyond the compositions of the fibers are not required tojoin the fluid distribution component and the airlaid component, thecomposite sheet is much softer and fluffier than materials provided inthe prior art.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a cross-sectional side view of a composite sheet in accordancewith at least one embodiment of the present invention;

FIG. 2 is a cross-sectional side view of a composite sheet in accordancewith at least one embodiment of the present invention in which thecomposite sheet includes a plurality of airlaid layers;

FIG. 3 is a cross-sectional side view of a composite sheet in accordancewith at least one embodiment of the present invention in which thecomposite sheet includes a coating layer deposited on the surface of theoutermost airlaid layer;

FIG. 4A is a schematic illustration of a system for preparing acomposite sheet in accordance with an embodiment of the presentinvention;

FIG. 4B shows a schematic illustration of a forming head for preparingan airlaid layer in accordance with at least one embodiment of thepresent invention;

FIG. 5 is a cross-sectional side view of a composite sheet in accordancewith at least one embodiment of the present invention in which thecomposite sheet includes a plurality of alternating ridges and channelsformed on the surface of the outermost airlaid layer;

FIG. 6 depicts fluid transport and distribution through a compositesheet material;

FIG. 7 is an illustration of an absorbent article in accordance with atleast one embodiment of the present invention; and

FIG. 8 is an illustration of an absorbent article in accordance with atleast one embodiment of the present invention in which the absorbentarticle is in the form of a feminine sanitary pad.

DETAILED DESCRIPTION

The present inventions now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the invention are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout. As used inthe specification, and in the appended claims, the singular forms “a”,“an”, “the”, include plural referents unless the context clearlydictates otherwise.

Definitions

For the purposes of the present application, the following terms shallhave the following meanings:

The term “fiber” can refer to a fiber of finite length or a filament ofinfinite length.

The term “staple fiber” refers to a fibers of finite length. In generalstaple fibers may have a length from about 2 to 200 millimeters (mm).

As used herein, the term “monocomponent” refers to fibers formed fromone polymer or formed from a single blend of polymers. Of course, thisdoes not exclude fibers to which additives have been added for color,anti-static properties, lubrication, hydrophilicity, liquid repellency,etc.

As used herein, the term “multicomponent” refers to fibers formed fromat least two polymers (e.g., bicomponent fibers) that are extruded fromseparate extruders. The at least two polymers can each independently bethe same or different from each other, or be a blend of polymers. Thepolymers are arranged in substantially constantly positioned distinctzones across the cross-section of the fibers. The components may bearranged in any desired configuration, such as sheath-core,side-by-side, segmented pie, island-in-the-sea, and so forth. Variousmethods for forming multicomponent fibers are described in U.S. Pat. No.4,789,592 to Taniguchi et al. and U.S. Pat. No. 5,336,552 to Strack etal., U.S. Pat. No. 5,108,820 to Kaneko, et al., U.S. Pat. No. 4,795,668to Kruege, et al., U.S. Pat. No. 5,382,400 to Pike, et al., U.S. Pat.No. 5,336,552 to Strack, et al., and 6,200,669 to Marmon, et al., whichare incorporated herein in their entirety by reference. Multicomponentfibers having various irregular shapes may also be formed, such asdescribed in U.S. Pat. No. 5,277,976 to Hogle, et al., U.S. Pat. No.5,162,074 to Hills, U.S. Pat. No. 5,466,410 to Hills, U.S. Pat. No.5,069,970 to Largman, et al., and 5,057,368 to Largman, et al., whichare incorporated herein in their entirety by reference.

As used herein, the terms “nonwoven,” “nonwoven web” and “nonwovenfabric” refer to a structure or a web of material which has been formedwithout use of weaving or knitting processes to produce a structure ofindividual fibers or threads which are intermeshed, but not in anidentifiable, repeating manner. Nonwoven webs have been, in the past,formed by a variety of conventional processes such as, for example,meltblown processes, spunbond processes, and staple fiber cardingprocesses.

As used herein, the term “carded fabric” refers to a nonwoven fabriccomprising staple fibers that are predominantly aligned and oriented inthe machine direction using a carding process.

As used herein, the term “meltblown” refers to a process in which fibersare formed by extruding a molten thermoplastic material through aplurality of fine, usually circular, die capillaries into a highvelocity gas (e.g. air) stream which attenuates the molten thermoplasticmaterial and forms fibers, which can be to microfiber diameter.Thereafter, the meltblown fibers are carried by the gas stream and aredeposited on a collecting surface to form a web of random meltblownfibers. Such a process is disclosed, for example, in U.S. Pat. No.3,849,241 to Buntin et al.

As used herein, the term “machine direction” or “MD” refers to thedirection of travel of the nonwoven web during manufacturing.

As used herein, the term “cross direction” or “CD” refers to a directionthat is perpendicular to the machine direction and extends laterallyacross the width of the nonwoven web.

As used herein, the term “spunbond” refers to a process involvingextruding a molten thermoplastic material as filaments from a pluralityof fine, usually circular, capillaries of a spinneret, with thefilaments then being attenuated and drawn mechanically or pneumatically.The filaments are deposited on a collecting surface to form a web ofrandomly arranged substantially continuous filaments which canthereafter be bonded together to form a coherent nonwoven fabric. Theproduction of spunbond non-woven webs is illustrated in patents such as,for example, U.S. Pat. Nos. 3,338,992; 3,692,613; 3,802,817; 4,405,297;and 5,665,300. In general, these spunbond processes include extrudingthe filaments from a spinneret, quenching the filaments with a flow ofair to hasten the solidification of the molten filaments, attenuatingthe filaments by applying a draw tension, either by pneumaticallyentraining the filaments in an air stream or mechanically by wrappingthem around mechanical draw rolls, depositing the drawn filaments onto aforaminous collection surface to form a web, and bonding the web ofloose filaments into a nonwoven fabric. The bonding can be any thermalor chemical bonding treatment, with thermal point bonding being typical.

As used herein, the term “air through thermal bonding” involves passinga material such as one or more webs of fibers to be bonded through astream of heated gas, such as air, in which the temperature of theheated gas is above the softening or melting temperature of at least onepolymer component of the material being bonded. Air through thermalbonding may involve passing a material through a heated oven.

As used herein, the term “thermal point bonding” involves passing amaterial such as one or more webs of fibers to be bonded between aheated calender roll and an anvil roll. The calender roll is typicallypatterned so that the fabric is bonded in discrete point bond sitesrather than being bonded across its entire surface.

As used herein, the term “polymer” generally includes, but is notlimited to, homopolymers, copolymers, such as, for example, block,graft, random and alternating copolymers, terpolymers, etc. and blendsand modifications thereof. Furthermore, unless otherwise specificallylimited, the term “polymer” shall include all possible geometricalconfigurations of the material, including isotactic, syndiotactic andrandom symmetries.

The term “composite”, as used herein, may be a structure comprising twoor more layers, such as a film layer and a fiber layer or a plurality offiber layers molded together. The two layers of a composite structuremay be joined together such that a substantial portion of their commonX-Y plane interface, according to certain embodiments of the invention.

Unless otherwise apparent from the context, the term “about” encompassesvalues within a standard margin of error of measurement (e.g., SEM) of astated value or variations ±0.5%, 1%, 5%, or 10% from a specified value.

Embodiments of the invention are directed to a composite sheet materialthat is particularly useful in the manufacture of absorbent articles,and in particular, disposable feminine hygiene products and diaperproducts. As explained in greater detail below, the composite sheetmaterial comprises a multilayer structure having a fluid acquistionlayerand one or more airlaid layers that are successively depositedoverlying the fluid acquisition layers. The airlaid layers comprise ablend of cellulose staple fibers and non-cellulose staple fibers thatare selected to provide a fabric that is particularly suited for use asa fluid/acquisition layer in an absorbent article.

With reference to FIG. 1, a composite sheet material in accordance withat least one embodiment of the invention is shown and designated byreference character 10. In the illustrated embodiment, the sheetmaterial comprises a fluid acquisition component 12 and an airlaidcomponent 14 overlying the fluid acquistion component. The fluidacquisition component includes at least one nonwoven layer having afirst outer surface 16 and a second outer surface 18. Similarly, theairlaid component includes a first outer surface 20 and a second outersurface 22.

In one embodiment, the outer surface 18 of the fluid acquisition iscomponent 12 is disposed adjacent and opposite outer surface 20 of theairlaid component 14. In preferred embodiments, the opposing outersurfaces 18, 20 of the fluid distribution and airlaid components 12, 14are disposed directly opposite each other so that the surfaces of eachcomponent are in contact with each other.

In some embodiments, the airlaid component 14 may comprise one or moreairlaid layers. In this regard, FIG. 2 illustrates an embodiment of theinvention in which the airlaid component comprises a plurality ofairlaid layers that are formed overlying the fluid acquisition component12. Preferably, each of the airlaid layers are adjacent to, and indirect contact with, immediately adjacent layers of the airlaidcomponent so that adjacent layers are in fluid communication withrespect to each other.

In general, the mass of the fluid acquisition component comprises fromabout 8 to 85 weight percent of the composite sheet, based on the totalweight of the composite sheet. In one embodiment, the mass of the fluidacquisition component comprises from about 20 to 75 weight percent ofthe composite sheet, and in particular, from about 30 to 60, based onthe total weight of the composite sheet.

The mass of the airlaid component comprises from about 15 to 92 weightpercent of the composite sheet, based on the total weight of thecomposite sheet. In one embodiment, the mass of the airlaid componentcomprises from about 20 to 80 weight percent of the composite sheet, andin particular, from about 30 to 70, based on the total weight of thecomposite sheet.

Composite sheets in accordance with the present invention areparticularly useful as a fluid AQDL component in the manufacture ofabsorbent articles. Typically, such fluid AQDL components need tobalance properties in order to quickly move fluids away from the skin ofthe wearer, and uniformly distribute them into the absorbent core of theabsorbent article. If the fluid is transported to quickly through theAQDL component, the fluid may not distribute laterally (in the x-ydirections) through the layer. This may result in too much fluid beinglocalized in one region of the absorbent core. Ideally, it is desirableto have the fluid move quickly through the fluid AQDL component while atthe same time, the fluid is distributed laterally through the component.This allows the fluid to be absorbed over a large surface area of theabsorbent core.

To achieve this desired balance, it is important that the fluid AQDLcomponent have good fluid absorption properties good wicking properties(capillary action of the fluid moving through the component), low fluidacquisition times (the length of time it takes for a material to absorba given amount of fluid) as well as good fluid retention properties. Thefirst three properties contribute to how quickly the fluid is moved awayfrom the skin of the wearer and into the absorbent core, and the fluidretention property helps to balance these properties to allow the fluidto be laterally distributed prior to transport into the absorbent core.

As absorbent articles are typically meant to worn by an individual, thecomfort of the material to the wearer is also important. If the materialis inflexible, stiff, or rigid, the wearer is most likely to reject theabsorbent article. Accordingly, it is desirable for the absorbentarticle to not only provide the balance of the above-describedproperties, but to also to have resiliency so to provide improvedcomfort and fit to the wearer.

The inventors of the present invention have found that composite sheetsin accordance with the invention provide a good balance of fluidabsorption, fluid wicking, fluid acquisition time, and fluid retention,as well as providing a composite sheet having good resiliency. As aresult, composite sheets in accordance with embodiments of the inventionare particularly useful as a AQDL component in the manufacture ofabsorbent articles.

In one aspect, composite sheets in accordance with embodiment of theinvention are characterized by fluid acquisition times ranging fromabout 0.75 seconds to about 2 seconds, and in particular, from about 0.8to 1.5 seconds, and in particular, from about 0.84 to 1.3 seconds.

In one aspect, composite sheets in accordance with embodiment of theinvention are characterized by a fluid absorption ranging from about 15to 30 g/g, and in particular, from about 20 to 26 g/g, and inparticular, from about 20 to 25 g/g.

In one aspect, composite sheets in accordance with embodiment of theinvention are characterized by a fluid retention ranging from about 8 to15 g/g, and in particular, from about 9 to 14 g/g, and in particular,from about 10 to 12 g/g.

In one aspect, composite sheets in accordance with embodiment of theinvention are characterized by a fluid wicking height ranging from about10 to 50 mm, and in particular, from about 15 to 45 mm, and moreparticularly, from about 15 to 40 mm.

In one aspect, composite sheets in accordance with embodiment of theinvention are characterized by a resiliency ranging from about 30 to60%, and in particular, from about 35 to 55%, and more particularly,from about 40 to 50%.

In one embodiment, composite sheets in accordance with the invention maybe characterized by a fluid acquisition time ranging from about 0.5seconds to about 2 seconds; a fluid absorption ranging from about 15 to30 g/g; a fluid retention ranging from about 8 to 15 g/g; a fluidwicking height ranging from about 10 to 50 mm; and a resiliency rangingfrom about 30 to 60%. For example, the composite sheet may have a fluidacquisition time ranging from about 0.65 to 1.5 seconds; a fluidabsorption ranging from about 20 to 26 g/g; a fluid retention rangingfrom about 9 to 14 g/g; a fluid wicking height ranging from about 15 to45 mm; and a resiliency ranging from about 35 to 55%. In certainembodiments, the composite sheet may have a fluid acquisition timeranging from about 0.84 to 1.3 seconds; a fluid absorption ranging fromabout 20 to 25 g/g; a fluid retention ranging from about 10 to 12 g/g; afluid wicking height ranging from about 15 to 40 mm; and a resiliencyranging from about 40 to 55%.

In a preferred embodiment, the composite sheet has a fluid acquisitionof about 1.25 seconds; a fluid absorption of about 25 g/g; a fluidretention of about 10 g/g; a fluid wicking height of about 40 mm; and aresiliency of about 40%.

The basis weight of the composite sheet may range from about 25 to 400grams per square meter (g/m²), and in particular, from about 40 to 225g/m², and more particularly, from about 50 to 180 g/m². In a preferredembodiment, the composite sheet has a basis weight that is about 50 to100 g/m².

The thickness of the composite sheet may range from about 1 to 6 mm, andin particular, from about 1.3 to 4.5 mm, and more particularly, fromabout 1.5 to 3.0 mm. In a preferred embodiment, the composite sheet hasa thickness that is about 1.6 to 2.5 mm.

Fluid Acquisition Layer

In one embodiment, the fluid acquisition component comprises a fluidacquisition layer comprising a nonwoven fabric having a relativelypermeable and porous structure so that a fluid, upon impinging on thesurface of the fluid acquisition layer, is quickly transported throughthe fluid acquisition layer, and into the airlaid component 14. Thepermeable and porous nature of the fluid acquisition layer may generallybe characterized by the density of the layer. For example, the densityof the fluid acquisition layer may be from about 0.02 to 0.07 g/cm³, andin particular, from about 0.03 to 0.06 g/cm³. In a preferred embodiment,the density of the fluid acquisition layer is from about 0.04 to 0.05g/cm³.

A wide variety of different nonwoven fabrics may be used as the fluidacquisition layer. In one embodiment, the nonwoven fabric of the fluidacquisition layer comprises a carded nonwoven fabric comprising staplefibers. Typical lengths of the staple fibers in the fluid acquisitionlayer may range from about 20 to 100 mm, and in particular, from about25 to 60 mm, and more particularly, from about 35 to 55 mm.

Other examples of nonwovens that may be used as the fluid acquisitionlayer may include latex bonded carded fabrics and spunlace nonwovens.The fibers of the fluid acquisition layer may be bonded in a variety ofmanners including, thermal bonding, resin bonding, stitch bonding,mechanical bonding, such as needle punch or hydroentanglement, and thelike.

The staple fibers may comprise monocomponent or multicomponent fibers.In one embodiment, the staple fibers comprise bicomponent fibers have asheath/core configuration. Examples of bicomponent fibers includeside-by-side, islands in the sea, and sheath/core arrangements.Preferably, the fibers have a sheath/core structure in which the sheathcomprises a first polymer component, and the core comprises a secondpolymer component. In this arrangement, the polymers of the first andsecond polymer components may be the same or different from each other.For example, in one embodiment, the sheath comprises a first polymercomponent, and the core comprises a second polymer component that isdifferent or the same as the first polymer component. In a preferredembodiment, the first and second polymer components of the bicomponentfibers are different from each other.

In some embodiments the staple fibers of the fluid acquisition layer mayhave a sheath/core configuration in which the core is centered relativeto the sheath. Alternatively, the core may be present in an off-setconfiguration relative to the sheath. In this configuration, the corenot centrally aligned relative to the sheath. As a result, when heat isapplied, such as during bonding, the fibers will have a tendency to curlor crimp due, which in turn may help provide loft to the fluidacquisition layer.

In one embodiment, the first polymer component of the sheath comprises apolymer having a lower melting temperature than that of the secondpolymer component comprising the core. The lower melting polymer of thesheath will promote bonding while the polymer component of the corehaving a higher melting temperature will provide strength to the fiberand thus to the final bonded nonwoven.

Generally, the weight percentage of the sheath to that of the core inthe fibers may vary widely depending upon the desired properties of thenonwoven fabric. For example the weight ratio of the sheath to the coremay vary between about 10:90 to 90:10, and in particular from about20:80 to 80:20. In a preferred embodiment, the weight ratio of thesheath to the core is about 60:40 to 40:60, with a weight ratio of about50:50 being preferred.

Generally, the fluid acquisition layer has a basis weight ranging fromabout 18 to 100 (g/m²), and in particular, from about 25 to 80 g/m², andmore particularly, from about 30 to 55 g/m². In a preferred embodiment,the fluid acquisition layer has a basis weight that is about 35 to 40g/m².

The thickness of the fluid acquisition layer may range from about 0.4 to4 mm, and in particular, from about 0.7 to 3 mm, and more particularly,from about 0.7 to 2 mm. In a preferred embodiment, the fluid acquisitionlayer has a thickness that is about 0.8 to 1.5 mm.

A wide variety of polymers may be used for preparing staple fibers foruse in the fluid acquisition layer. Examples of suitable fibers includemay include polyolefins, such as polypropylene and polyethylene, andcopolymers thereof, polyesters, such as polyethylene terephthalate(PET), polytrimethylene terephthalate (PTT), and polybutyleneterephthalate (PBT), nylons, polystyrenes, copolymers, and blendsthereof, and other synthetic polymers that may be used in thepreparation of fibers. In one embodiment, the staple fibers have asheath/core configuration comprising a polyethylene sheath and apolypropylene core. In other embodiments, the staple fibers may have asheath/core configuration comprising a polyethylene sheath and apolyester core, such as a core comprising polyethylene terephthalate.

In some embodiments, the staple fibers may comprise a blend of fiberssuch as a blend of bicomponent staple fibers having a polyethylenesheath and a polyethylene terephthalate core, and bicomponent staplefibers having a polyethylene sheath and a polypropylene core. In oneembodiment, the fibers of the fluid acquisition layer may includeeccentric bicomponent staple fibers having a polyethylene sheath and apolyethylene terephthalate core, a fineness of 4.3 dtex, and an averagelength of 38 to 51 mm. Examples of such fibers are available fromIndoramaPolyester Industries Public Company Limited under the productname TS47.

The above noted polymers are generally considered to be derived fromsynthetic sources, such as a petroleum derived polymer. In someembodiments, it may be desirable to provide a fluid acquisition layercomprising one or more sustainable polymer components. In contrast topolymers derived from petroleum sources, sustainable polymers aregenerally derived from a bio-based material. In some embodiments, asustainable polymer component may also be considered biodegradeable. Aspecial class of biodegradable product made with a bio-based materialmight be considered as compostable if it can be degraded in a composingenvironment. The European standard EN 13432, “Proof of Compostability ofPlastic Products” may be used to determine if a fabric or film comprisedof sustainable content could be classified as compostable.

In one such embodiment, the fluid acquisition layer comprises staplefibers comprising a sustainable polymer component. Preferably, thestaple fibers are substantially free of synthetic materials, such aspetroleum-based materials and polymers. For example, fibers comprisingthe fluid acquisition layer may have less than 25 weight percent ofmaterials that are non-bio-based, and more preferably, less than 20weight percent, less than 15 weight percent, less than 10 weightpercent, and even more preferably, less than 5 weight percent ofnon-bio-based materials, based on the total weight of the fluidacquisition layer.

In one embodiment, sustainable polymers for use may include polylacticacid and bio-based derived polyethylene. Generally, polylactic acidbased polymers are prepared from dextrose, a source of sugar, derivedfrom field corn. In North America corn is used since it is the mosteconomical source of plant starch for ultimate conversion to sugar.However, it should be recognized that dextrose can be derived fromsources other than corn. Sugar is converted to lactic acid or a lacticacid derivative via fermentation through the use of microorganisms. Thusbesides corn other agricultural based sugar source could be usedincluding sugar beets, sugar cane, wheat, cellulosic materials, such asxylose recovered from wood pulping, and the like. Similarly, bio-basedpolyethylene can be prepared from sugars that are fermented to produceethanol, which in turn is dehydrated to provide ethylene. A preferredsustainable polymer for use in the present invention comprisespolylactic acid (PLA).

In certain embodiments, the sheath and the core both comprise a PLAresin. In these embodiments, a PLA spunbond nonwoven fabric may beprovided that is substantially free of synthetic polymer components,such as petroleum-based materials and polymers. For example, the fibersof the PLA spunbond nonwoven fabric may have a bicomponent arrangementin which the both components are PLA based to thus produce a fiber thatis 100% PLA. As used herein, “100% PLA” may also include up to 5%additives including additives and/or masterbatches of additives toprovide, by way of example only, color, softness, slip, antistaticprotection, lubricity, hydrophilicity, liquid repellency, antioxidantprotection and the like. In this regard, the nonwoven fabric maycomprise 95-100% PLA, such as from 96-100% PLA, 97-100% PLA, 98-100%PLA, 99-100% PLA, etc. When such additives are added as a masterbatch,for instance, the masterbatch carrier may primarily comprise PLA inorder to facilitate processing and to maximize sustainable contentwithin the fibers. For example, the PLA staple fibers of the fluidacquisition layer may comprise one or more additional additives. In suchembodiments, for instance, the additive may comprise at least one of acolorant, a softening agent, a slip agent, an antistatic agent, alubricant, a hydrophilic agent, a liquid repellent, an antioxidant, andthe like, or any combination thereof.

In one embodiment, the PLA polymer of the sheath may be the same PLApolymer as that of the core. In other embodiments, the PLA polymer ofthe sheath may be a different PLA polymer than that of the core. Forexample, the bicomponent fibers may comprise PLA/PLA bicomponent fiberssuch that the sheath comprises a first PLA grade, the core comprises asecond PLA grade, and the first PLA grade and the second PLA grade aredifferent (e.g., the first PLA grade has a lower melting point than thesecond PLA grade). By way of example only, the first PLA grade maycomprise up to about 5% crystallinity, and the second PLA grade maycomprise from about 40% to about 50% crystallinity.

In some embodiments, for instance, the first PLA grade may comprise amelting point from about 125° C. to about 135° C., and the second PLAgrade may comprise a melting point from about 155° C. to about 170° C.In further embodiments, for example, the first PLA grade may comprise aweight percent of D isomer from about 4 wt. % to about 10 wt. %, and thesecond PLA grade may comprise a weight percent of D isomer of about 2wt. %.

For example, in one embodiment, the core may comprise a PLA having alower % D isomer of polylactic acid than that of the % D isomer PLApolymer used in the sheath. The PLA polymer with lower % D isomer willshow higher degree of stress induced crystallization during spinningwhile the PLA polymer with higher D % isomer will retain a moreamorphous state during spinning. The more amorphous sheath will promotebonding while the core showing a higher degree of crystallization willprovide strength to the fiber and thus to the final bonded web. In oneparticular embodiment, the Nature Works PLA Grade PLA 6752 with 4% DIsomer can be used as the sheath while NatureWorks Grade 6202 with 2% DIsomer can be used as the core.

In some embodiments, the sheath may comprise a bio-based polyethylene,and the core may comprise a PLA polymer.

In some embodiments, the sheath may comprise a PLA polymer and the corea synthetic polymer, such as polypropylene.

Airlaid Layer

The airlaid component 14 includes at least one airlaid layer comprisinga blend of cellulose staple fibers and non-cellulose staple fibers. Asdiscussed in greater detail below, the at least one airlaid layer isdeposited onto a surface of the fluid distribution component, and theresulting composite sheet material is then through air bonded to form acoherent composite structures in which the staple fibers of both thefluid acquisition layer and the airlaid layer are bonded to each other.

During the process of making the composite sheet material, a mixture ofcellulose staple fibers and non-cellulose staple fibers are first mixedin an air stream, and then deposited onto a surface of the fluidacquisition layer. Thereafter, the fibers of the fluid acquisition layerand airlaid layer are bonded to each other by introducing a stream ofheated gas, such as air, through the composite sheet material. Forexample, in one embodiment the composite sheet material is passedthrough an oven that it heated to a temperature that is above thesoftening temperature of the non-cellulose staple fibers, which causesthe low-melt sheath polymer component of the staple fibers to at leastpartially soften and flow so that upon cooling the fibers fuse and bondto adjacent cellulose and non-cellulose fibers.

A wide variety of different cellulose materials may be used for thecellulose fibers. For example, digested cellulose fibers from softwood(derived from coniferous trees), hardwood (derived from deciduous trees)or cotton linters can be utilized. Fibers from Esparto grass, bagasse,kemp, flax, and other lignaceous and cellulose fiber sources may also beutilized. Other fibers include absorbent natural fibers made fromregenerated cellulose, polysaccharides or other absorbent fiber-formingcompositions. For reasons of cost, ease of manufacture anddisposability, preferred fibers are those derived from wood pulp (e.g.,cellulose fibers). In particular, examples of suitable materials includetreated and untreated pulp, including pulps of hardwood, softwood,straw, chemical pulp, fluff pulp, chemi-mechanical pulp, thermalmechanical pulp, and mixtures thereof. Suitable cellulose fibers may beobtained from Weyerhauser under the product designations NB416 and NB405, International Paper Super soft M, Georgia Pacific under the productdesignations 4821, 4822, and 4823, and mixtures thereof.

The cellulose fibers generally have a fiber length that is about 0.8 to10 mm, and in particular, from about 2 to 8 mm, and more particularly,from about 2 to 5 mm.

Suitable materials for the non-cellulose staple fibers for use in theairlaid layer may comprise monocomponent or multicomponent fibers, ormixtures of moncomponent and multicomponent fibers. In a preferredembodiment, the non-cellulose staple fibers of the airlaid layercomprise bicomponent fibers having a sheath/core configuration.

Examples of polymers that may be used to prepare the non-cellulosefibers include those discussed above for use in the fluid acquisitionlayer. For example, the non-cellulose fibers may comprise sustainablepolymers, such as PLA and bio-based polyethylene, synthetic fibers, andcombinations thereof. In one embodiment, the non-cellulose staple fibersmay comprise a sheath comprising a bio-based polyethylene, and a corecomprising a PLA polymer. In other embodiments, the non-cellulose staplefibers may comprise a PLA polymer sheath and a PLA polymer core, whereinthe PLA polymers may be the same or different from each other.

In other embodiments, the sheath may comprise a PLA polymer and the corea synthetic polymer, such as polypropylene.

In one embodiment, the non-cellulose staple fibers may comprisebicomponent staple fibers having a polyethylene sheath and apolyethylene terephthalate core. One such example is bicomponent staplefiber having a fineness of 2.2 dtex, and an average length of 3 mm,which are available from Toray Chemical Korea Inc. under the productname EZBON A (UN-204). A further example is an eccentric bicomponentstaple fibers having a polyethylene sheath and a polyethyleneterephthalate core. Such a fiber is available from IndoramaPolyesterIndustries Public Company Limited under the product name TS47 (afineness of 4.3 dtex, and an average length of 3 mm). Another example isa bicomponent staple fibers having a polyethylene sheath and apolyethylene terephthalate core is available from Trevira under theproduct designation T255 staple fibers. These staple fibers have afineness of 4.3 dtex, and an average length of 3 mm.

In another embodiment, the non-cellulose staple fibers may comprisebicomponent staple fibers having a polyethylene sheath and apolypropylene core. One such example is a staple fiber having a finenessof 4.0 dtex, and an average length of 40 mm, which are available fromYangzhou Petrochemical Co. Ltd. under the product name Y116. Anotherexample of bicomponent staple fibers having a polyethylene sheath and apolypropylene core, a denier of 6.0, and an average length of 51 mm, areavailable from JiangNan High Polymer Fiber under the product designationJNGX-PZ11-6*51L.

In some embodiments, the non-cellulose fibers may comprise blends offibers, such as blends comprising bicomponent PE/PET and PE/PP staplefibers.

The non-cellulose staple fibers typically have lengths ranging fromabout 3 to 15 mm, and in particular, from about 3 to 10 mm, and moreparticularly, from about 3 to 6 mm.

Collectively, the basis weight of the airlaid layer(s) may range fromabout 7 to 300 g/m², and in particular, from about 20 to 200 g/m², andmore particularly, from about 30 to 100 g/m². In a preferred embodiment,the airlaid layer has a basis weight that is about 50 g/m².

In some embodiments, one or more of the airlaid layers may include asuper absorbent polymer or super absorbent fibers that are mixed withthe cellulose and non-cellulose fibers. The super absorbent polymer orsuper absorbent fibers may be present in only one layer of the air laidcomponent or present in multiple airlaid layers of the airlaidcomponent. When present, the super absorbent polymer or super absorbentfibers may be present in an amount from about 10 to 50 weight percent,and in particular, from about 10 to 35 weight percent, based on thetotal weight of the air laid layer in which the super absorbent polymeror super absorbent fibers are present.

Additional Layers

In some embodiments, the composite sheet may further comprise apolymer-based layer that is deposited on the outer surface 22 of theairlaid component. In this regard, FIG. 3 illustrates an embodiment ofthe invention in which the composite sheet material 10 comprises acoating layer 24 disposed on the outer surface of the airlaid component14. In one embodiment, the coating layer may be applied a compositioncomprising a carrier, such as water or an organic solvent, and apolymeric material dispersed in the carrier. For example, in oneembodiment, the coating layer may comprise a latex formulation of anaqueous polymer dispersion comprising ethylene vinyl acetate, acrylates,polyacrylates, phenylethylenes, butadienes, styrene butadiene-acrylicacids, polyvinyl alcohols, and mixtures thereof.

In one embodiment, the latex formulation comprises a polymer producedfrom the monomers vinyl acetate and ethylene, which is available fromWacker under the product name VINNAPAS® 192, with a solid constituentranging from 50 to 55%.

The coating layer may be applied to the composite sheet material invariety of different ways, such as, spray coating, foam coating, kisscoating, and the like.

In the case of an aqueous dispersion or emulsion, the coating layer isapplied as a liquid, which may then be cured and dried to form a solidcoating adhered to the composite sheet. The amount of the coating layeradded to the composite sheet, following any drying and cure step istypically from about 1 to 5 weight percent, and in particular, fromabout 1.5 to 3 weight percent, and more particularly, from about 1.75 to2.25 weight percent, based on the total weight of the composite sheet.

Process of Preparing the Composite Sheet.

With reference to FIG. 4A, a system and associated process for preparingthe composite sheet material is shown and designated with referencecharacter 26. The system 26 includes a source of fabric for use as thefluid acquisition layer 12. In the illustrated embodiment, the source isshown as a spool 28 on which the previously formed fluid acquisitionlayers if wound. However, it should be recognized that the system mayinclude a fabric forming device, for example, a card or spinning beam,for preparing the nonwoven fabric of the fluid acquisition layer in acontinuous line with respect to the rest of the system 26.

As shown, the nonwoven fabric of the fluid acquisition layer 12 isremoved from the spool 28 and deposited on a collection surface 29, suchas an endless belt. The fluid acquisition layer is then transported to aseries of airlaid fabric forming heads (30 a, 30 b, 30 c). At eachforming head a stream of cellulose and non-cellulose staple fibers arehomogeneously mixed to form a stream of mixed staple fibers. Eachforming head then deposits the mixed stream of staple fibers onto thesurface of the fluid acquisition layer 12. A vacuum 31 a, 31 b, 31 c, ispositioned underneath the collection surface, and below each of theforming heads to assist in depositing the mixed stream of fibers ontothe fluid acquisition layer 12. The system may optionally include one ormore pairs of compaction rollers 32 a, 32 b that are disposed followingeach forming head. When present, compaction rollers 32 a, 32 b may beheated. For example, the compaction rollers 32 a, 32 b may be heated ata temperature ranging from about 90 to 110° C.

Although three airlaid forming heads are shown, it should be understoodthat the system may include any number of forming heads depending on thedesired number of airlaid layers that are deposited onto the fluidacquisition layer 12. For example, the number of airlaid forming headsmay range from 1 to 10, such as 2 to 8, 3 to 6, and 4 to 5. It shouldalso be recognized that during operation of the system, one or more ofthe forming heads may not be used.

With reference to FIG. 4B, a forming head that may be used in certainembodiments of the invention is illustrated. As can be seen, the forminghead 30 a includes a plurality of agitators 35 that create a turbulentflow within the forming head. The turbulent flow causes the celluloseand non-cellulose staple fibers to mix and form a homogenous mixture.The forming head also includes a screen 33 that limits/controls theoutput of the staple fibers from the forming head and thereby helps toform an evenly distributed airlaid layer.

Turning back to FIG. 4A, the composite sheet material with the thusdeposited airlaid layers is transported to a first heating oven 36 a.The first heating oven is typically maintained at a temperature that issufficient to soften and melt the non-cellulose fibers of the airlaidlayers. This melting causes the polymers to flow and fuse to adjacentfibers to provide a coherent composite sheet. For example, inembodiments in which the non-cellulose staple fibers comprised abicomponent fiber having a polyethylene sheath, the composite sheetmaterial may be heated to a temperature above the melting point of thesheath, but below the melting point of the core. For polyethylene, thetemperature of the oven will typically be from about 120 to 150° C.

In some embodiments, the system may include one or more embossing rolls34 that may be used to impart an embossed pattern on the surface of thecomposite sheet. In some embodiments, the system may also include a pairof calibration rolls 38 to adjust the thickness of the composite sheet,and/or assist in interlayer bonding between adjacent layers. Calibrationroll 38 may be define a nip or be gapped. In some embodiments, thecalibration roll is heated; in other embodiments, the calibration rollis not heated.

Prior to this initial thermal bonding in the first heating oven, thecomposite sheet is transported to an application station 35 at whichpoint a coating layer may be applied to the surface of the outermostairlaid layer. This coating layer may be applied using conventionaltechniques such as are known in the art including, spray coating, kissroll application, and the like. In a preferred embodiment, a coating ofan aqueous latex dispersion is applied to the surface of the compositeweb. In some embodiments, a second application coating layer may beapplied to the opposite side of the coating via application station 37.

Following application of the optional second coating layer, or any othermaterials to the surface of the composite sheet, the composite sheet istransported to a second heating oven 36 b that is maintained at atemperature that dries and cures the previously applied coating layers.Optionally, the composite sheet material may be further heated in athird oven 36 c.

The bonded and dried composite sheet material may then be wound ontoroll 39. In some embodiments, the composite sheet may be cutcontinuously in the machine direction to form a plurality of individualcomposite sheets that are each wound onto separate rolls.

In some embodiments, it may be desirable to emboss a pattern onto theairlaid component of the composite sheet. For example, using theembossing roll 34 shown in FIG. 4A. In this regard, FIG. 5 shows anembodiment of the invention in which the surface 22 of the compositesheet 10 has a plurality of alternating ridges R and channels/grooves Cthat are defined on the surface of the outermost airlaid layer. In theconstruction of an absorbent article, the fluid acquisition layer istypically disposed towards the top sheet whereas the airlaid componentis disposed towards the absorbent core. Fluid entering the compositesheet material is distributed through the fluid acquisition layer andinto the airlaid layer(s). As it is transported towards the absorbentcore, the plurality of ridges and channels helps to further distributethe fluid so that it may be more evenly distributed throughout theairlaid layer, and hence, throughout the absorbent core.

The pattern of alternating ridges and channels typically extend in themachine direction of the composite sheet material, but otherorientations are possible, such as diagonally or in the cross direction,or in a nonlinear, such as serpentine, and/or noncontinuousconfiguration.

The pattern may be produced by a roll in which having a pattern ofalternating raised surfaces and grooves that extend circumferentiallyabout the roll. In some embodiments, the roll may be heated and pressuremay be applied to the surface of the composite sheet material to helpfacilitate formation of the pattern of alternating grooves and ridges.The widths of each groove (e.g., distance between adjacent ridges) mayvary depending upon the intended application of the absorbent article,but will typically range from about 0.2 to 10 mm, and in particular,from about 1 to 6 mm, and more particularly, from about 2 to 3 mm. Thedepth of each groove will typically be about 0.1 to 5 mm, and inparticular, from about 0.3 to 3 mm.

As discussed previously, the composite sheet material of the presentinvention is particularly useful as an AQDL component in absorbentarticles. In particular, the composite sheet is able to rapidlytransport fluids through the fluid acquisition layer and then distributethe fluid laterally through the one or more airlaid layers. Thistransport of fluid is illustrated in FIG. 6.

Absorbent Articles

Composite sheets in accordance with the present invention may be used ina wide variety of different articles, and in particular, a wide varietyof absorbent articles.

With reference to FIG. 7, an embodiment of an absorbent article(“diaper”) in accordance with embodiments of the present invention isshown and broadly designated by reference number 40. The diaper 40includes a core region 42 in which an absorbent core 44 is disposed. Achassis region 46 surrounds the core region 42, and includes a front 48,back 50, and front and back waist regions 52 a, 52 b. The chassis regioncomprised of front, back and core regions generally has a compositestructure comprising a liquid permeable topsheet and a liquidimpermeable backsheet that are attached to each other along opposingsurfaces to define a cavity there between in which the absorbent core isdisposed.

Suitable materials for the topsheet, backsheet, and absorbent core maygenerally comprise any materials conventionally used in the manufactureof absorbent articles.

As shown in FIG. 7, the diaper also includes a composite sheet material10 in accordance with at least one embodiment of the present invention.The composite sheet 10 defines a fluid acquisition distribution system90 (i.e., AQDL component) of the absorbent article. As discussed above,the composite sheet 10 defines a fluid distribution/acquisitioncomponent that helps to efficiently facilitate transfer of fluid fromthe wearer to the absorbent core 44.

In some embodiments, the front and back regions of the diaper also eachincludes a pair of ears 54 that are disposed in the waist regions of thediaper. (As used herein, the term “disposed” is used to mean that anelement(s) of the diaper is formed (joined and positioned) in aparticular place or position as a unitary structure with other elementsof the diaper or as a separate element joined to another element of thediaper.) The ears 54 provide an elastically extensible feature thatprovides a more comfortable and contouring fit by initially conformablyfitting the diaper to the wearer and sustaining this fit throughout thetime of wear well past when the diaper has been loaded with exudatessince the elasticized side panels allow the sides of the diaper toexpand and contract.

In addition, the ears 54 develop and maintain wearing forces (tensions)that enhance the tensions developed and maintained by a fasteningsystem, discussed in greater detail below, to maintain the diaper 40 onthe wearer and enhance the waist fit. As shown in FIG. 7, the diaperincludes a pair of back ears 56 a, 56 b which are joined to the backregion 50 of the diaper chassis proximate to the back waist region 52 b,and a pair of front ears 58 a, 58 b, which are joined to the frontregion 48 of the diaper chassis proximate of the front waist region 52a.

The front and back ears may be joined to the chassis region 46 by anybonding method known in the art such as adhesive bonding, pressurebonding, heat bonding, and the like. In other embodiments, the frontand/or back ears may comprise a discrete element joined to the chassisregion with the chassis region 46 having a layer, element, or substratethat extends over the front and/or back ear. For example, each ear maycomprise a portion of the diaper chassis region that extends laterallyoutwardly from and along the side edge 60 of the chassis region to alongitudinal edge 62 of the diaper 40. In one embodiment, the earsgenerally extend longitudinally from the end edge 64 of the diaper 40 tothe portion of the longitudinal edge 62 of the diaper 20 that forms theleg opening (this segment of the longitudinal edge 62 being designatedas leg edge 66). In some embodiments, the ears may comprise a separatefabric or web that has been joined to the topsheet or the backsheet. Inother embodiments, each ear may be formed by the portions of thetopsheet and the backsheet that extend beyond the side edges of theabsorbent core 44.

In one embodiment, the diaper 40 may also include elastic leg cuffs 70for providing improved containment of fluids and other body exudates.Each elasticized leg cuff 70 may comprise several different embodimentsfor reducing the leakage of body exudates in the leg regions. (The legcuff can be and is sometimes also referred to as leg bands, side flaps,barrier cuffs, or elastic cuffs.) U.S. Pat. No. 3,860,003 entitled“Contractable Side Portions for a Disposable Diaper” issued to Buell onJan. 14, 1975, describes a disposable diaper which provides acontractible leg opening having a side flap and one or more elasticmembers to provide an elasticized leg cuff (gasketing cuff). U.S. Pat.No. 4,909,803 entitled “Disposable Absorbent Article Having ElasticizedFlaps” issued to Aziz and Blaney on Mar. 20, 1990, describes adisposable diaper having “stand-up” elasticized flaps (barrier cuffs) toimprove the containment of the leg regions. U.S. Pat. No. 4,695,278entitled “Absorbent Article Having Dual Cuffs” issued to Lawson on Sep.22, 1987, describes a disposable diaper having dual cuffs including agasketing cuff and a barrier cuff. U.S. Pat. No. 4,704,115 entitled“Disposable Waist Containment Garment” issued to Buell on Nov. 3, 1987,discloses a disposable diaper or incontinent garment havingside-edge-leakage-guard gutters configured to contain free liquidswithin the garment. Each of these patents are incorporated herein byreference. U.S. Pat. No. 6,476,289 entitled “Garment Having ElastomericLaminate” describes various elastic leg cuff configurations that mayalso be used in embodiments of the present invention.

In a preferred embodiment, the leg cuffs may comprises a fabric layerhaving an SMS structure comprising a plurality of elastic strands thatare incorporated into the leg cuff structure. Preferably, the leg cuffscomprises a material having liquid barrier properties.

One example of a fabric for use in forming leg cuffs comprises an SMSfabric having a spunbond nonwoven layer comprising bicomponent fibershaving a first polymer component sheath and a second polymer componentcore. Examples of materials for the sheath and core include polyolefins,such as polypropylene and polyethylene, polyesters, PLA based polymers,and the like. In one embodiment, the bicomponent fibers comprise apolypropylene sheath, and a PLA core. An example of a polypropylenematerial for use in this embodiment may have a melt flow rate (MFR)between 20 to 40 g/10 min (measured in accordance with ASTM D1238 (190°C./2.16 kg)) such as, for example, provided by Total Petrochemicals andRefining USA, Inc. of La Port, Tex., 77571 USA as grades M 3766(metallocene polypropylene) and 3764 or 3866 (Zeigler Nattapolypropylene). A suitable material for use as the PLA core is availablefrom Nature Works PLA as Grade 6202 with 2% D Isomer. The meltblownlayer may comprise a polypropylene having an MFR of 1,300 g/10 min(measured in accordance with ASTM D1238 (190° C./2.16 kg)) such as, forexample, provided by Total Petrochemicals and Refining USA, Inc. of LaPort, Tex., 77571 USA as grade 3962.

In a second example, the leg cuffs may comprise an SMS fabric having aspunbond nonwoven layer comprising bicomponent fibers having a PLAsheath and a PLA core, and a meltblown layer comprising PLA fibers. Anexample of a suitable PLA material for use as the sheath is PLA grade6752 with 4% D Isomer, and an example of a suitable PLA material for useas the core is PLA grade 6202 with 2% D Isomer, both of which areavailable from NatureWorks. A suitable material for the PLA meltblownfibers is PLA grade 6252, which is also available from NatureWorks.

In a third embodiment, the leg cuffs may comprise a fabric having an SMSstructure in which the spunbond nonwoven layers comprise a bicomponentfabric having a polypropylene sheath and a PLA core. Examples ofsuitable materials for the sheath and core are described above. Themeltblown layer may comprise meltblown fibers comprising a blend of PLAand polypropylene that has been reclaimed from spunbond bicomponentfibers comprised of PP/PLA using the process taught in InternationalApplication PCT/US 2015/012658.

In a fourth embodiment, the leg cuffs may comprise a fabric having anSMS structure in which the spunbond nonwoven layers comprise abicomponent fabric having a PLA sheath and a PLA core. Examples ofsuitable materials for the sheath and core are described above. As inthe third embodiment discussed above, the meltblown layer may comprisemeltblown fibers comprising a blend of PLA and polypropylene that hasbeen reclaimed from spunbond bicomponent fibers comprised of PP/PLAusing the process taught in International Application No.PCT/US2015/012658.

Preferably, spunbond fabrics for forming the leg cuffs have asheath/core ratio of approximately 30/70 to 70/30. In one embodiment,the basis weight of the SMS fabric is between about 8 g/m² and 15 g/m².Preferably, the meltblown content comprises about 10 to 30 weight %,based on the total weight of the SMS fabric. In some embodiments, theSMS fabric for use in forming the leg cuffs has a hydrohead value ofgreater than about 50 mm as measured in accordance with INDA Test MethodWSP 80.6.

In some embodiments, the diaper 40 may also include elastic elementsthat are disposed around one or more of the waist region 52 and theelastic cuffs. For example, the diaper may also comprise at least oneelastic waist feature (not represented) that helps to provide improvedfit and containment. The elastic waist feature is generally intended toelastically expand and contract to dynamically fit the wearer's waist.The elastic waist feature preferably extends at least longitudinallyoutwardly from at least one waist edge of the absorbent core andgenerally forms at least a portion of the end edge of the absorbentarticle. Disposable diapers can be constructed so as to have two elasticwaist features, one positioned in the front waist region and onepositioned in the back waist region. The elastic waist feature may beconstructed in a number of different configurations including thosedescribed in U.S. Pat. Nos. 4,515,595; 4,710,189; 5,151,092; and5,221,274.

In some embodiments, the elastic features may comprise elastic elementscomprising elastic strands or threads that are contractably affixedbetween the topsheet and backsheet of the diaper. Such strands orthreads can be comprised of a bio-based material, such as naturalrubber. As noted above the natural rubber strands are covered bynonwoven, such as the topsheet and/or backsheet to insure elasticcomponent does not directly contact the wearer's skin.

The absorbent article may include a fastening system. The fasteningsystem can be used to provide lateral tensions about the circumferenceof the absorbent article to hold the absorbent article on the wearer asis typical for taped diapers. This fastening system is not necessary forpull on style of absorbent articles, such as training pants or adultincontinence absorbent articles, since the waist region of thesearticles is already bonded.

The fastening system usually comprises a fastener such as tape tabs,hook and loop fastening components, interlocking fasteners such as tabs& slots, buckles, buttons, snaps, and/or hermaphroditic fasteningcomponents, although any other known fastening means are generallyacceptable. A landing zone is normally provided on the front waistregion for the fastener to be releasably attached. When fastened, thefastening system interconnects the front waist region 52 a and the backwaist region 52 b. When fastened, the diaper 44 contains acircumscribing waist opening and two circumscribing leg openings.

The fastening system may comprise an engaging member 80 and a receivingmember 82 (also referred to as a landing zone). The engaging member 80may comprise hooks, loops, an adhesive, a cohesive, a tab, or otherfastening mechanism. The receiving member 82 may comprise hooks, loops,a slot, an adhesive, a cohesive, or other fastening mechanism that canreceive the engaging member 80. Suitable engaging member 80 andreceiving member 82 combinations are well known in the art and includebut are not limited to hooks/loop, hooks/hooks, adhesive/polymeric film,cohesive/cohesive, adhesive/adhesive, tab/slot, and button/button hole.Suitably, the fastening system may comprise a polymer derived from abio-based material.

In this regard, FIG. 7 further shows a fastening system in which theengaging member comprises a pair of tabs 80 that are joined to the backears 56 a, 56 b, and an associated landing zone 82 disposed on a frontsurface 84 of the diaper 40. In some embodiments, the tabs may include apressure sensitive adhesive for adhesively attaching the tabs to thelanding zone.

Some exemplary surface fastening systems are disclosed in U.S. Pat. Nos.3,848,594; 4,662,875; 4,846,815; 4,894,060; 4,946,527; 5,151,092; andU.S. Pat. No. 5,221,274 issued to Buell. An exemplary interlockingfastening system is disclosed in U.S. Pat. No. 6,432,098. The fasteningsystem may also provide a means for holding the article in a disposalconfiguration as disclosed in U.S. Pat. No. 4,963,140 issued toRobertson et al.

The fastening system may also include primary and secondary fasteningsystems, as disclosed in U.S. Pat. No. 4,699,622 to reduce shifting ofoverlapped portions or to improve fit as disclosed in U.S. Pat. Nos.5,242,436; 5,499,978; 5,507,736; and 5,591,152.

In a preferred embodiment, the fastening system can employ a hook andloop as described in U.S. Pat. No. 9,084,701. In a preferred embodiment,the hook and loop fastening system comprises a female fastening materialmade of fibrous material and a male fastening material with hooksconfigured for the fibrous material.

In one embodiment, the female loop material comprises bonded bicomponentfibers comprising a bio-based material, such as spunbond bicomponentfibers having a PLA, and a sheath comprising a sugar cane derivedpolyethylene polymer. Examples of such materials are described above. Anexample of a suitable PLA polymer for the core in is available fromNatureWorks as PLA Grade 6202.

A second fiber for use as the female loop component providing 50bio-based material content comprises a sheath of petroleum basedpolypropylene polymer and a PLA core derived from NatureWorks under theproduct name PLA Grade 6202. Preferred polypropylenes for use in thisembodiment will typically have a melt flow rate (MFR) between 20 to 40g/10 min (measured in accordance with ASTM D1238 (190° C./2.16 kg)) suchas for example provided by Total Petrochemicals and Refining USA, Inc.of La Port, Tex., 77571 USA as grades M 3766 (metallocene polypropylene)and 3764 or 3866 (Zeigler Natta polypropylene).

A further example of fibers for constructing a female loop material,providing 50% bio-based material content, comprise spunbond bicomponentfibers in which the core comprises a lignin based polymer and a sheathcomprising a petroleum based polyethylene. Such fibers are disclosed asexamples 4, 5, 6, 7, 8, and 9 in European Patent No. EP 2,630,285 B1 andU.S. Patent Publication No. 2014/0087618.

Substitution of the petroleum based polyethylene sheath in theseexamples with a sheath comprised of either the sugar cane derivedpolyethylene available from Braskem S.A. or the corn derived PLAavailable from NatureWorks, both polymers disclosed above, would providefibers having up to a 100% bio-based material content.

A further example of a fiber that can be used for constructing thefemale loop material is a bicomponent fiber having a core of (PLA), anda sheath comprising PLA. For example, in one embodiment, the core maycomprise a PLA having a lower % D isomer of polylactic acid than that ofthe % D isomer PLA polymer used in the sheath. The PLA polymer withlower % D isomer will show higher degree of stress inducedcrystallization during spinning while the PLA polymer with higher D %isomer will retain a more amorphous state during spinning. The moreamorphous sheath will promote bonding will the core showing a higherdegree of crystallization will provide straight to the fiber and thus tothe final bonded web.

In one particular embodiment, the Nature Works PLA Grade PLA 6752 with4% D Isomer can be used as the sheath while NatureWorks Grade 6202 with2% D Isomer can be used as the core.

A further example of fibers for use in the female loop material,providing at least 50% bio-based material content may comprise a 50/50blend of cotton fibers and a petroleum based polymer, such aspolypropylene. Examples of polypropylene staple fibers useful to formsuch fabrics are available from Fibervisions Corporation as Grade T-198.Examples of cotton fibers for use to form such nonwoven fabrics includefibers sold under the product name TRUECOTTON® available from TJ BeallCompany, and fibers sold under the product name HIGH-Q ULTRA® availablefrom Barnhardt Manufacturing Company.

The male hooks use in this fastening stem for the preferred embodimentare also comprised of significant sustainable content. The malefastening material including the hooks can be made by casting, molding,profile extrusion, or microreplications where the polymer used is cornderived PLA such as is available from NatureWorks. NatureWorks providesa selection of grades for injection molding that could be used to makesuch hooks including Grades 3001D, 3052D, 3100HP and 3251D.

With reference to FIG. 8, a further embodiment of an absorbent articlein accordance with an embodiment of the present invention is illustratedin which the absorbent article is in the form of a feminine sanitarypad, broadly designated by reference character 100.

Pad 100 may include a topsheet 102, backsheet 104, and an absorbent core106 disposed there between. Preferably, topsheet 102 and backsheet 104are joined to each other about along opposing outer edges to define acontinuous seam 108 that extends about the periphery 110 of the pad 100.Continuous seam 108 may comprise a heat seal that is formed fromthermally bonding the topsheet and backsheet to each other. In otherembodiments, continuous seam 108 is formed by adhesively bonding thetopsheet and backsheet to each other.

Suitable materials for the topsheet, backsheet, and absorbent core maycomprise materials typically used in the construction of absorbentarticles.

As shown, pad 100 includes a composite sheet 10 defining a fluid AQDLcomponent 112. The AQDL component is disposed between the absorbent core106 and the topsheet 102. As discussed above, the composite sheetdefining the fluid distribution/acquisition component comprises a fluidacquisition layer comprising a carded nonwoven and at least one airlaidlayer comprising a blend of cellulose staple fibers and non-cellulosefibers, in which the fibers of the layers are thermally bonded to eachother.

Various components of the absorbent article are typically joined viathermal or adhesive bonding. Examples of suitable adhesives includepolyethylene, polypropylene, or ethylene vinyl acetate based meltadhesives. In some embodiments, the adhesive may comprise a bio-basedadhesive. An example of a bio-based adhesive is a pressure sensitiveadhesive available from Danimer Scientific under the product code 92721.

In yet another aspect, certain embodiments of the invention provideabsorbent articles. In accordance with certain embodiments, theabsorbent article may include a composite sheet in accordance with thepresent invention

In this regard, composite sheets prepared in accordance with embodimentsof the invention may be used in wide variety of articles andapplications. For instance, embodiments of the invention may be used forpersonal care applications, for example products for babycare (diapers,wipes), for femcare (pads, sanitary towels, tampons), for adult care(incontinence products), or for cosmetic applications (pads).

EXAMPLES

The following examples are provided for illustrating one or moreembodiments of the present invention and should not be construed aslimiting the invention.

Unless otherwise defined, the technical terms used in the followingembodiments have the same meaning as commonly understood by thoseskilled in the art to which this invention pertains. The test reagentsused in the following embodiments, unless otherwise specified, areconventional reagents; the said experimental methods, unless otherwisespecified, are conventional methods.

Test Methods

Thickness was determined in accordance with EDANA 30.5-99 using adigital thickness tester. In accordance with this test, a sample ofmaterial is positioned between two plates under a pressure (0.5 kPa),and the distance between the two plates is reported in units of “mm.”

Carry out sample taking and cutting according to different productrequirements, the size edge of sample to be tested to the edge of theupper side of the instrument should not be less than 5 mm; the sampleshould be acclimated for at least 4 hours under constant temperature andhumidity condition (23±2° C.; relative Humidity: 50%±5%). If acclimationof the sample will not be carried out, the temperature and humidity atthat moment should be recorded while performing measurement, only forreference of comparison.

Compression and Resilience:

After taking samples from the aged products without 4 hours ofacclimation, complete the first test within 30 minutes, the thickness isT1; after keeping the sample for 4 hours, measure the thickness again,the thickness value is T2, the rebound resilience is expressed by thepercentage of (T2−T1/T1).

Test thickness under different pressure by measuring same area ofmaterial continuously to simulate the ‘human’ touch/press process.

Caliper under 0.5 kPa: T1

Caliper under 2.1 kPa: T2

Caliper under 0.5 kPa: T3%

Compression=(T2-T1)/T2×100%

% Resiliency=(T3-T2)/T2×100%

Basis Weight

Basis weight was measured in accordance with EDANA 40.3-90.

Mass determination: the mass of unit area is the mass determination ofthe sample (gram weight), with unit of g/m².

Tester: electronic balance (accuracy to 0.001 gram), screens are setaround the balance to prevent air flow and other interference factorsfrom impacting the balance.

The samples are required to balance for at least 4 hours under constanttemperature and humidity condition (23±2° C.; relative Humidity:50%±5%). If the balance will not be carried out for the on-linereal-time test, the temperature and humidity at that moment should berecorded while performing measurement, only for reference of comparison.

Place the sample to be tested on the balance, after the reading of thebalance becomes stable, record the weight in units of grams.

Mass determination (GSM)==AB

Where: GSM: the determined mass of a sample;

A: weight of a sample;

B: area of a sample.

Tensile strength and elongation at break were measured in accordancewith EDANA 20.2-89.

Tensile strength: the tension required to pull a sample with specifiedsize to break at constant speed. The percentage of the length when thesample is pulled to break to the original length of the sample is theelongation at breaking, in unit of “%”.

Tester: Zwick 2.5 strength tester

Cut the sample to a size of 200 mm×25.4 mm, the sample is required toacclimate for at least 4 hours under constant temperature and humiditycondition (23±2° C.; relative Humidity: 50%±5%). If acclimation is notdone for on-line real-time test, the temperature and humidity at thatmoment should be recorded while performing measurement, only forreference of comparison.

Set the testing procedure according to following test parameters:

Maximum test limit: 100 N;

Test speed: 254 mm/min;

Clamping distance: 51 mm;

Clamping pressure: 5 bars.

Fluid penetration speed was measured in accordance with EDANA 150.5-02.

Liquid penetration speed: when 5 ml 0.9% sodium chloride solutionpenetrates the sample, record the transit time of the liquid by circuitconductivity, in unit of second.

Tester: Lister liquid penetration instrument.

Fluid absorption was measured in accordance with EDANA 10.4-02.

Liquid absorption capability: after soaking the sample in liquid for atime duration of 10 minutes, the percentage of total weight increase isthe absorption capability of the sample.

Liquid absorption capability: after soaking the sample in liquid for atime duration of 10 minutes, the total weight increase is the absorptioncapability of the sample. (g/g)

Retention: after soaking the sample in liquid for a time duration of 10minutes, and keep it in a container for 2 minutes, then carefully placea 1976 g weight on the sample, the weight increase is the waterretaining capacity of the sample. (g/g)

Rewet (g)

Place the sample to be tested on the absorption core (the 150 gsm SAPcore (18% SAP) is applied during the test). Place a φ60 mm cylinder atthe center position of the sample to be tested, take 15 ml brine and putit into the cylinder, and start the time counting at the same time,after 5 minutes, place many layers of filter paper with known weight onthe surface of sample (till the top layer of filter paper does notabsorb any liquid), and place a 1.2 kg standard pressing block on thefilter paper at the same time, start to count the time again, remove thestandard pressing block after a duration of 1 minute, weigh the mass offilter paper on the sample surface by means of a balance, its increasedweight is the reverse osmosis value. The smaller the value, the betterrewet performance will be expected.

Fluid holding capability was measured using the following procedure. Asample of the material was soaked in a liquid for a time duration of 10minutes, and then kept in a container for 2 minutes. A 1976 g weight wasthen placed on the sample. The percentage of weight increase is thewater retaining capacity of the sample.

Fluid Acquisition was measured in accordance with EDANA 150.5-02.

Acquisition: when 5 ml 0.9% sodium chloride solution penetrates thesample, record the transit time of the liquid by circuit conductivity,in unit of second.

Tester: Lister liquid penetration instrument.

Anti-reverse osmosis performance was measured in accordance withreference standards: EDANA 150.5-02, ERT 154.0-02.

Take a sample to be tested, place a φ60 mm cylinder at the centerposition of the sample to be tested, take 15 ml brine and put it intothe cylinder, and start the time counting at the same time, after 5minutes, place many layers of filter paper with known weight on thesurface of sample (till the top layer of filter paper does not absorbany liquid), and place a 1.2 kg standard pressing block on the filterpaper at the same time, start to count the time again, remove thestandard pressing block after a duration of 1 minute, weigh the mass offilter paper on the sample surface by means of a balance, its increasedweight is the reverse osmosis value. The smaller the value, the betterthe anti-reverse osmosis performance will be.

Suction range of liquid was measured with reference standard EDANA10.4-02.

Liquid suction range: after one end of vertically suspended sample issoaked in the liquid for 5 minutes, the height that the liquid risesalong the sample is the suction range of the sample.

Sample size: the sample size is 30 mm×200 mm

The sample is required to balance for at least 4 hours under constanttemperature and humidity condition (23±2° C.; relative Humidity:50%±5%).

Place the test stand into a plastic container, secure two rulers on thestand vertically, add 0.9% NaCl solution or distilled water (uponcustomer's request), adjust the liquid level to the scales on two rulersbecome 15 mm. Add and mix proper amount of blue coloring agent in thesolution so as to make it easy to read. Rotate the rulers out of theliquid level, and wipe clean the water on the surface, fix the wellprepared sample on the rulers by using fish tail clips, pay attention toalign the lower end of the ruler with the zero point. Rotate the rulersout of the liquid level, and start count the time at the same time.Incline the end of the ruler extended into the liquid slightly backwardto allow a certain gap between the ruler and the sample. At the sametime the timer sounds after five minutes, rotate two rulers out of theliquid level and read the readings (observe the height that the liquidrises along the sample, read the value at peak point, if the individualvalue is too high on the sample edge, round it and read the value atother peak point). The test result is the actual value is subtracted by15 mm, that is the value of liquid suction range.

Wicking rate: was measured in accordance with reference standard: EDANA10.4-02.

After one end of vertically suspended sample is soaked in the liquid for5 minutes, the height that the liquid rises along the sample is thesuction range of the sample.

Sample size: the sample size is 30 mm×200 mm.

The sample is required to balance for at least 4 hours under constanttemperature and humidity condition (23±2° C.; relative Humidity:50%±5%).

Place the test stand into a plastic container, secure two rulers on thestand vertically, add 0.9% NaCl solution or distilled water (uponcustomer's request), adjust the liquid level to the scales on two rulersbecome 15 mm. Add and mix proper amount of blue coloring agent in thesolution so as to make it easy to read. Rotate the rulers out of theliquid level, and wipe clean the water on the surface, fix the wellprepared sample on the rulers by using fish tail clips, pay attention toalign the lower end of the ruler with the zero point. Rotate the rulersout of the liquid level, and start count the time at the same time.Incline the end of the ruler extended into the liquid slightly backwardto allow a certain gap between the ruler and the sample. At the sametime the timer sounds after five minutes, rotate two rulers out of theliquid level and read the readings (observe the height that the liquidrises along the sample, read the value at peak point, if the individualvalue is too high on the sample edge, round it and read the value atother peak point). The test result is the actual value is subtracted by15 mm, to provide the wicking rate.

The materials used in the composite sheets and comparative nonwovenfabrics are identified below. All percentages are weight percents unlessindicated otherwise. All physical property and compositional values areapproximate unless indicated otherwise.

“Pulp-1” refers to an untreated pulp staple fiber available fromWeyerhaeuser under the product name NB416.

“Pulp-2” refers to a treated pulp staple fiber available fromWeyerhaeuser under the product name NB405.

“PE/PET-1” refers to bicomponent staple fibers having a polyethylenesheath and a polyethylene terephthalate core, a fineness of 2.2 dtex,and an average length of 3 mm, which are available from Toray ChemicalKorea Inc. under the product name EZBON A (UN-204).

“PE/PET-2” refers to eccentric bicomponent staple fibers having apolyethylene sheath and a polyethylene terephthalate core, having afineness of 4.3 dtex, and an average length of 40 mm, which areavailable from IndoramaPolyester Industries Public Company Limited underthe product name TS47.

“PE/PET-3” refers to bicomponent staple fibers having a polyethylenesheath and a polyethylene terephthalate core, having a fineness of 4.3dtex, and an average length of 3 mm, available from Trevira under theproduct designation T255 staple fibers.

“PE/PP-1” refers to bicomponent staple fibers having a polyethylenesheath and a polypropylene core, a denier of 4.0, and an average lengthof 40 mm, which are available from Yangzhou Petrochemical Co. Ltd. underthe product name Y116.

“PE/PP-2” refers to bicomponent staple fibers having a polyethylenesheath and a polypropylene core, a denier of 6.0, and an average lengthof 51 mm, which are available from JiangNan High Polymer Fiber under theproduct designation JNGX-PZ11-6*51L.

“PET-1” refers to polyethylene terephthalate staple fibers having adenier of 9.0, and an average length of 51 mm, which are available fromIndoramaPolyester Industries Public Company Limited under the productdesignation INR-207Z-TG21/TG31.

“Latex” refers to an aqueous polymer dispersion produced from themonomers vinyl acetate and ethylene, which is available from Wackerunder the product name VINNAPAS® 192. The Latex formulation has a solidconstituent ranging from 51 to 53%.

In the Inventive Examples 1-4 set forth below, composite sheets inaccordance with embodiments of the present invention were prepared bydepositing 2-3 airlaid fabric layers overlying an air through bonded(ATB) carded fabric layer. The carded ATB fabrics used in InventiveExamples 1-4 are as follows.

“ATB-1” refers to a carded fabric comprising a mixture of staple fibersin which 30% by weight of the fibers comprise PE/PP-1 fibers and 70% byweight comprise PE/PET-2 fibers. The carded fabric had a basis weight of30 g/m².

“ATB-2” refers to a carded fabric comprising a mixture of staple fibersin which 20% by weight of the fibers comprise PE/PP-1 fibers and 80% byweight comprise PE/PET-2 fibers. The carded fabric had a basis weight of35 g/m².

“ATB-3” refers to a carded fabric comprising a mixture of staple fibersin which 20% by weight of the fibers comprise PET-1 fibers and 80% byweight comprise PE/PP-2 fibers. The carded fabric had a basis weight of55 g/m².

INVENTIVE EXAMPLES

Unless otherwise indicated, the inventive examples were preparedaccording to the following procedures. In a first step, a previouslyprepared a fabric comprised of an air through bonded, carded nonwovenfabric (ATB fabric) was provided an unwound from a spool and transferredonto a continuous mesh belt. This ATB fabric defines the fluidacquisition layer, and hence, the fluid distribution component, of thecomposite sheet. The ATB fabric is then transported to the airlaidforming heads which deposit a mixture of cellulose and non-cellulosestaple fibers onto the ATB fabric to form airlaid component of thecomposite sheet. In the following examples, 2 to 3 airlaid layers weredeposited overlying the ATB fabric. The airlaid fabric layers wereformed with a horizontal screen type forming technology with airlaidequipment available from M&J Company.

The cellulose and non-cellulose fibers of the airlaid layer(s) werehomogeneously mixed using an air stream and a plurality of blades thatcreate a turbulent flow within each forming head. A vacuum is positionedunder the belt to assist in collecting the staple fibers onto thesurface of the ATB fabric layer. After a first airlaid layer wasdeposited, a pre-stress roller was optionally positioned between thefirst and second forming heads. The composite sheet is then transportedto the second airlaid forming area, where a second airlaid fabric layeris deposited overlying the previously deposited airlaid layer. Thisprocess is repeated until the desired amount of airlaid layers aredeposited onto the composite sheet. The resulting composite sheet maythen be stabilized with a heated roller that was heated to a temperatureof 80 to 100° C. The composite sheet was then transported to, and passedthrough, a first heated oven, which was maintained at a temperature fromabout 120 to 150° C. The temperature of the first oven was selected tosoften and melt the non-cellulose fibers of both the airlaid layers aswell as the fluid acquisition layer (e.g., ATB layer) so that the fibersmelt and flow together to form a coherent composite sheet.

Prior to passing through the oven, the composite sheet was transportedto a coating station at which point a coating layer comprised of a latexformulation was deposited onto the surface of the outermost airlaid toform a coating layer. The composite sheet was then heated in an oven todry and cure the latex coating. The oven was maintained at a temperaturefrom about 120 to 150° C. Optionally, the composite sheet may further bedried in a third oven.

Inventive Example 1

Inventive Example 1 was prepared by depositing two airlaid layers onto apreviously prepared fabric of ATB-1. The two airlaid layers comprised ahomogenous fiber mixture of Pulp 1 fibers and PE/PET-1 fibers. Followingdeposition of the two airlaid layers, a coating of the Latex formulationwas applied to the surface of the outermost airlaid layer. The compositesheet material was then successively passed through a series of ovens tobond the fibers to each other, and to dry and cure the Latexformulations. The dried add-on weight of the Latex layer was 2 weightpercent, based on the total weight of Inventive Example 1. The resultingcomposite sheet had a basis weight of 70 g/m².

The composite sheet of Inventive Example 1 had structure as set forth inTable 1 below.

TABLE 1 Structure and composition of Composite Sheet of InventiveExample 1 Percent of Percent of each layer Percent of each materialBasis in sheet each layer in per layer weight Layer Materials (%) sheet(%) (g/m²) Latex Latex 2.0  2.0 100% 1.40 coating Airlaid Pulp-1 22.129.6 74.6 15.46 Layer 2 PE/PET-1 7.5 25.4 5.25 Airlaid Pulp-1 18.1 25.670.7 12.65 Layer 1 PE/PET-1 7.5 29.3 5.25 ATB ATB-1 42.9 42.9 100% 30

Inventive Example 2

Inventive Example 2 was prepared by depositing two airlaid layers onto apreviously prepared fabric of ATB-2. The two airlaid layers comprised ahomogenous fiber mixture of Pulp 1 fibers and PE/PET-1 fibers. Followingdeposition of the two airlaid layers, a coating of the Latex formulationwas applied to the surface of the outermost airlaid layer. The compositesheet material was then successively passed through a series of ovens tobond the fibers to each other, and to dry and cure the Latexformulations. The dried add-on weight of the Latex layer was 2 weightpercent, based on the total weight of Inventive Example 2. The resultingcomposite sheet had a basis weight of 75 g/m².

The composite sheet of Inventive Example 1 had structure as set forth inTable 2 below.

TABLE 2 Structure and composition of Composite Sheet of InventiveExample 2 Percent of Percent of Basis each layer Percent of eachmaterial weight in sheet each layer in per layer per layer LayerMaterials (%) sheet (%) (g/m²) Latex Latex 2.0  2.0 100% 1.50 coatingAirlaid Pulp-1 16.3 27.5 72.6 14.96 Layer 2 PE/PET-1 7.5 27.4 5.65Airlaid Pulp-1 19.9 23.9 68.4 12.65 Layer 1 PE/PET-1 7.5 31.6 5.25 ATBATB-2 46.7 46.7 100% 35

Inventive Example 3

Inventive Example 3 was prepared by depositing two airlaid layers onto apreviously prepared fabric of ATB-2. The two airlaid layers comprised ahomogenous fiber mixture of Pulp 1 fibers and PE/PET-1 fibers. Followingdeposition of the two airlaid layers, a coating of the Latex formulationwas applied to the surface of the outermost airlaid layer. The compositesheet material was then successively passed through a series of ovens tobond the fibers to each other, and to dry and cure the Latexformulations. The dried add-on weight of the Latex layer was 2 weightpercent, based on the total weight of Inventive Example 3. The resultingcomposite sheet had a basis weight of 85 g/m².

The composite sheet of Inventive Example 3 had structure as set forth inTable 3 below.

TABLE 3 Structure and composition of Composite Sheet of InventiveExample 3 Percent of Percent of Basis each layer Percent of eachmaterial weight in sheet each layer per layer per layer Layer Materials(%) in sheet (%) (g/m²) Latex Latex 2.0  2.0 100% 1.7 coating AirlaidPulp-1 23 30.5 75.4 19.5 Layer 2 PE/PET-1 7.5 24.6 6.38 Airlaid Pulp-118.8 26.3 71.5 16.0 Layer 1 PE/PET-1 7.5 28.5 6.38 ATB ATB-2 41.2 41.2100% 35

Inventive Example 4

Inventive Example 4 was prepared by depositing three airlaid layers ontoa previously prepared fabric of ATB-3. The three airlaid layerscomprised a homogenous fiber mixture of Pulp 1 fibers and PE/PET-1fibers. Following deposition of the three airlaid layers, a coating ofthe Latex formulation was applied to the surface of the outermostairlaid layer. The composite sheet material was then successively passedthrough a series of ovens to bond the fibers to each other, and to dryand cure the Latex formulations. The dried add-on weight of the Latexlayer was 2 weight percent, based on the total weight of InventiveExample 4. The resulting composite sheet had a basis weight of 95 g/m².

The composite sheet of Inventive Example 4 had structure as set forth inTable 4 below.

TABLE 4 Structure and composition of Composite Sheet of InventiveExample 4 Percent of Percent of each ma- Percent of each material Basisterial in each layer in per layer weight Layer Materials sheet (%) sheet(%) (g/m²) Latex Latex 2.0  2.0 100% 1.9 coating Airlaid Pulp-1 10.513.1 80.2 10.01 Layer 3 PE/PET-1 2.6 19.8 2.47 Airlaid Pulp-1 10.5 14.174.5 10.01 Layer 2 PE/PET-1 3.6 25.5 3.42 Airlaid Pulp-1 9.0 12.8 70.48.58 Layer 1 PE/PET-1 3.8 29.6 3.61 ATB ATB-2 57.9 57.9 100% 55

Comparative Examples Comparative Examples 1-3

Comparative Examples 1-3 were airlaid nonwoven fabrics having basisweights of 70, 80 and 95 g/m², respectively. The nonwoven fabricscomprised a blend of Pulp 1 staple fibers and PE/PET-3 staple fibers. Alatex formulation of the Latex was applied to the each of ComparativeExamples 1-3 as an as dried amount of 6.0%, 6.0%, and 6.5 weight %,respectively, based on total weight of each of the fabrics. ComparativeExample 1 included 71% Pulp 1 fibers and 23% PE/PET-3 fibers;Comparative Example 2 included 70% Pulp 1 fibers and 24% PE/PET-3fibers; and Comparative Example 3 included 73.5% Pulp 1 fibers and 20%PE/PET-3 fibers. The fabrics were dried in one or more ovens attemperatures from 150 to 160° C. The fabrics of Comparative Examples 1-3were provided by Fitesa China Airlaid Co. Ltd. of Tianjin, China.

Comparative Examples 4-5

Comparative Example 4 comprised an air through bonded (ATB) nonwovenfabric with a basis weight of 40 g/m², and comprised of a fiber mixtureof 20 weight % PE/PP-1 fibers and 80 weight % PE/PET-2 staple fibers.Comparative Example 5 comprised an ATB nonwoven fabric with a basisweight of 55 gsm, and comprised of a fiber mixture of 20 weight % PET-1fibers and 80 weight % PE/PP-2 staple fibers.

Comparative Example 6

Comparative Example 6 comprised a nonwoven fabric comprised of PET resinbonded fibers with a basis weight of 45 g/m².

Comparative Examples 7-9

Comparative Examples 7-9 were spunbond fabrics having a basis weights of50, 60, and 70 g/m², respectively. The spunbond fabrics were comprisedof polypropylene continuous filaments that included 0.5 weight % TiO₂ asa whitener. The filaments were calender bonded with a calendering rollhaving an oval/elliptical 18% bonding pattern at a temperature of about160° C. The fabrics of Comparative Examples 7-9 were obtained fromShandon Kanjie Nonwovens.

Comparative Examples 10-11

The nonwoven fabrics of Comparative Examples 10 and 11 were spunlacenonwoven fabrics with basis weights of 50 g/m² and 70 g/m²,respectively. Comparative Example 10 comprised 50% by weight of PETfibers having a fineness of 1.67 dtex, and 50% by weight of viscosefibers having a fineness of 1.67 dtex and lengths of 38 mm. ComparativeExample 11 comprised 50% by weight of PET fibers (antimony free) havinga fineness of 1.67 dtex, and 50% by weight of viscose fibers having afineness of 1.67 dtex and lengths of 38 mm.

Inventive Examples 1-4 and comparative Examples 1-11 were evaluated forproperties desirable for use as an acquisition/fluid acquisition layerin the construction of absorbent articles. As discussed previously, itis desirable for such fabrics/materials to exhibit a good balance ofproperties including acquisition, absorption, and retention of fluids.It is also desired that the fabric have good fluid wicking propertieswhich will permit the fluid to be distributed throughout the compositesheet prior to being transported into the core. In addition, resiliencyof the fabric (i.e., composite sheet) is desirable to provide comfort tothe wearer. To show the suitability for the inventive composite sheetsfor use in absorbent articles, these properties were all evaluated. Theresults are summarized in Table 5 below.

Inventive Example 5

Inventive Example 5 was prepared in accordance with the proceduresdiscussed above. The fluid acquisition layer comprised an air throughbonded carded fabric with a basis weight of about 20 g/m², and comprised30% by weight of the fibers comprise PE/PP-1 fibers and 70% by weightcomprise PE/PET-2 fibers. The first airlaid layer comprised 79.31%Pulp-1 staple fibers and 20.69% by weight of PE/PET-1 staple fibers. Thebasis weight of the airlaid layer was about 50 g/m². The two layeredcomposite sheet material had a thickness of about 1 mm. The overallbasis weight of the composite sheet was 70 g/m². An emulsion coatingcomprised of the Latex formulation was sprayed onto the outer surface ofthe airlaid fabric. Table 6 below summarizes the structure andcomposition of the composite sheet of Inventive Example 5.

TABLE 6 Composition of Inventive Example 5 Carded ABT Cellulose stapleBicomponent fabric fiber staple fiber Latex Fluid acquisition 100.00%   0%   0%   0% layer First fiber layer    0% 79.31% 20.69%   0% 2%emulsion here indicates the percentage of mass in total 2.00% determinedmass of the product

Inventive Example 6

Inventive Example 6 comprised a three layered composite sheet having abasis weight of about 85 g/m², and a thickness of about 1.75 mm. Thefluid acquisition layer comprised a carded ATB fabric comprising 30% byweight of the fibers comprise PE/PP-1 fibers and 70% by weight comprisePE/PET-2 fibers, and with a basis weight of 35 g/m². The airlaidcomponent of the composite sheet comprised two airlaid layers that weredeposited successively overlying the fluid acquisition layer. Bothairlaid layers comprised a blend of Pulp-1 staple fibers and PE/PET-1staple fibers. An emulsion coating comprised of the Latex formulationwas sprayed onto the outer surface of the airlaid fabric at a driedadd-on amount of about 2 weight percent. Inventive Example 6 wasprepared in accordance with the process steps discussed above. Table 7below summarizes the structure and composition of the composite sheet ofInventive Example 6.

The structure of the composite quick-permeable airlaid paper iscomprised of three layers, the determined mass of quick-permeableacquisition distribution layer takes about 41.20% of total determinedmass of the product, the determined mass of the first fiber layer takesabout 26.34% of total determined mass of the product, the determinedmass for the fiber layer takes about 30.46% of the total determinedweight of the product, the latex takes about 2.00% of the totaldetermined weight of the product. The distribution of various componentsat various layers is given in Table 7 below, the ratio in the table isexpressed by the percentage of mass of various materials at the layer.

TABLE 7 Composition of Inventive Example 6 Carded ABT Cellulose stapleBicomponent fabric fiber staple fiber Latex Fluid 100.00%    0%   0%  0% acquisition layer First airlaid    0% 71.51% 28.49%   0% layerSecond airlaid    0% 75.36% 24.64%   0% layer 2% emulsion here indicatesthe percentage of mass in total 2.00% determined mass of the product

Inventive Example 7

Inventive Example 7 comprised a four layered composite sheet having abasis weight of about 140 g/m², and a thickness of about 3.10 mm. Thefluid acquisition layer comprised a carded of ATB-3 with a basis weightof 55 g/m². The airlaid component of the composite sheet comprised threeairlaid layers that were deposited successively overlying the fluidacquisition layer. The first airlaid layer comprised a blend of Pulp-2staple fibers and PE/PET-1 staple fibers. The second and third airlaidlayers comprised a blend of Pulp-1 staple fibers and PE/PET-1 staplefibers. An emulsion coating comprised of the Latex formulation wassprayed onto the outer surface of the airlaid fabric at a dried add-onamount of about 2 weight percent. Inventive Example 7 was prepared inaccordance with the process steps discussed above. Table 8 belowsummarizes the structure and composition of the composite sheet ofInventive Example 7.

The structure of the composite quick-permeable airlaid paper iscomprised of three layers, the determined mass of quick-permeableacquisition distribution layer takes about 41.20% of total determinedmass of the product, the determined mass of the first fiber layer takesabout 26.34% of total determined mass of the product, the determinedmass for the fiber layer takes about 30.46% of the total determinedweight of the product, the latex takes about 2.00% of the totaldetermined weight of the product. The distribution of various componentsat various layers is given in Table 8 below, the ratio in the table isexpressed by the percentage of mass of various materials at the layer.

The fluid acquisition layer comprised about 39.29 weight % of thecomposite sheet, based on the total weight of the composite sheet. Thefirst, second, and third airlaid layers comprised about 16.07%, 21.43%,and 21.43%, respectively, based on the total weight of the compositesheet. A layer of the Latex was applied at a dried add-on amount ofabout 1.79%, based on the total weight of the composite sheet. The useof Pulp-2 (treated pulp) in the first airlaid provides several benefits,such as a much softer and fluffier effect, and which also allows thefirst airlaid layer to form density gradient with the second and thirdairlaid layers.

TABLE 8 Composition of Inventive Example 7 Cellulose Cellulose Bicom-Carded staple staple ponent ABT fiber fiber staple fabric Pulp-1 Pulp-2fiber Latex Fluid 100.00%    0%    0%    0%   0% acquisition layer Firstairlaid    0%    0% 66.67% 33.33%   0% layer Second airlaid    0% 75.00%   0% 25.00%   0% layer Third airlaid    0% 75.00%    0% 25.00%   0%layer 2% emulsion here indicates the percentage of mass in total 1.79%determined mass of the product

Inventive Example 8

In this example, an inventive composite sheet is prepared in accordancewith the structure of the composite sheet of Inventive Example 6.However, in this example, a plurality of alternating ridges and valleysis created on the outer surface of the outermost airlaid layer (e.g.,third airlaid layer) by passing the sheet material in contact with aroll having a patterned surface. During this step, pressure and heat areapplied to form a plurality of alternating ridges and grooves thatextend longitudinally along the machine direction length of thecomposite sheet. The surface of the pattern roll comprises a pluralityof grooves/channels having a depth (e.g., 1 mm), and that are spacedapart from adjacent grooves/channels (e.g., a spacing of 3 mm). Theplurality of grooves/channels extend circumferentially around thesurface of the roll. The temperature of the pattern roll is preferablynot more than 120° C. The pressure applied by the patterned roll to theoutermost airlaid layer can be adjusted according to the desired depth,which is generally not more than 60 Nmm, of the grooves/stripes formedon the outer surface of the composite sheet. Adjustment to temperatureand pressure can be done according to the requirement of the endproducts. The products with grooves/stripes can be obtained by thesubsequent processing process after the composite sheet is embossed.

In the following comparative Examples (Comparative Examples 12-14) thesame processes as described above were used in making the fabrics.

Comparative Example 12

Comparative Example 12 comprised an airlaid fabric having a basis weightof about 80 g/m², and a thickness of about 1.3 mm. The fabric wasprepared by depositing three airlaid fabric layers overlying a papersubstrate layer. Suitable materials for the paper substrate layer mayinclude NKA130 series made by Golden HongYe Paper or 17 gsm productsmade by Havix.

The airlaid fabric comprised a blend of cellulose staple fibers andnon-cellulose bicomponent PLA fibers. The following materials may beused for the cellulosic fibers in the airlaid layers: Pulp-1(Weyerhauser NB416), International Paper Super soft M, or GeorgiaPacific 4821, 4822, 4823 and mixtures thereof. The cellulose fibersgenerally have a fiber length that is about 2 to 5 mm. The non-cellulosestaple fibers comprised bicomponent fibers having a PLA sheath and a PLAcore. The fineness of PLA/PLA bicomponent fibers were 2.2 dtex/6 mm. Themelting point temperature of the PLA polymer of the sheath was about130° C., and the melting point temperature of the PLA polymer of thecore was about 160° C.

The structure of the airlaid fabric was comprised of four layers, thedetermined mass of the first layer takes about 16% of total determinedmass of the product, the determined mass of the second layer takes about23% of total determined mass of the product, the determined mass for thethird layer takes about 29% of the total determined weight of theproduct, the determined mass for the third layer takes about 32% of thetotal determined weight of the product. Both sides of the material weresprayed with water at 10% of total determined mass during the process.

The distribution of various components at various layers is given inTable 9 below.

TABLE 9 Composition of Comparative Example 12. Lining Cellulosic PLA/PLA(13 gsm) fiber bicomponent fiber Paper substrate layer 100%   0%  0%First airlaid layer 0% 60% 40% Second airlaid layer 0% 45% 55% Fourthlayer 0%  0% 100% 

Comparative Example 13

Comparative Example 13 comprised a 4-layer fabrics having a basis weightof about 150 g/m², and a thickness of about 1.3 mm. The same materialsas in Comparative Example 12 were used in Comparative Example 13. Thepaper substrate layer had a basis weight of 17 g/m².

The structure of the airlaid paper was comprised of four layers, thedetermined mass of the first layer takes about 11% of total determinedmass of the product, the determined mass of the second layer takes about25% of total determined mass of the product, the determined mass for thethird layer takes about 31% of the total determined weight of theproduct, the determined mass for the third layer takes about 33% of thetotal determined weight of the product. And both sides of the materialwere sprayed with water of 10% of total determined mass during theprocess. The distribution of various components at various layers isgiven in Table 10 below.

TABLE 10 Composition of Comparative Example 13. Lining CellulosicPLA/PLA (17 gsm) fiber Composite fiber Paper substrate layer 100%   0% 0% First airlaid layer 0% 70% 30% Second airlaid layer 0% 50% 50%Fourth layer 0%  0% 100% 

Comparative Example 14

Comparative Example 14 comprised a 4-layer fabric having a basis weightof about 150 g/m², and a thickness of about 1.3 mm. The same materialsas in Comparative Example 12 were used in Comparative Example 13. Thepaper substrate layer had a basis weight of 17 g/m².

The total determined mass of this embodiment's airlaid paper is about175 g/m², and the thickness was about 1.45 mm. The cellulose fibers inthe airlaid layer comprised Pulp-1 staple fibers with fiber lengths ofabout 2-5 mm. The bi-component staple fibers were comprised of a core ofpolypropylene (PP), and a sheath of polyethylene (PE). The fiber lengthswere about 3-6 mm, and the fineness was about 1.7-3.0 dtex.

The base nonwoven fabric layer had a basis weight of 22 g/m², andcomprised a polypropylene spunbonded nonwoven fabric. The superabsorbent polymer was from Sandia-930, or from manufacturers asStockhausen, Sumitomo, Shokubai and etc., the fourth layer in was alatex coating that was a sprayed on latex emulsion comprised of theLatex formulation discussed above.

The structure of the fabric of Comparative Example 14 comprised of fourlayers. The determined mass of the first layer takes about 12.6% oftotal determined mass of the product, the determined mass of the secondlayer takes about 27.4% of total determined mass of the product, thedetermined mass for the third layer takes about 30% of the totaldetermined weight of the product, the determined mass for the forthlayer takes about 28% of the total determined weight of the product, andthe emulsion of 32% of the total amount will be sprayed on the forthlayer. The distribution of various components at various layers is givenin Table 11 below.

TABLE 11 Composition of Comparative Example 14. Lining non-woven SuperPoly- Bicomponent Cellulosic fabrics absorbent ethylene Composite fiber(22 gsm) polymer (SAP) powder fiber Base nonwoven  0% 100%   0%   0%  0%fabric layer Second layer 62% 0%  0% 25.5% 12.5%  Third layer 50% 0% 50%  0%  0% Forth layer 62% 0% 25%   0% 13% The emulsion of 2% of the totalamount will be sprayed on the forth layer

In Table 12, below, Inventive Examples 5-8 were evaluated and comparedto Comparative Examples 12-14. With respect to the blind testing, 20individuals were randomly selected to evaluate the softness, fluffinessof material by their feeling and the dry and crisp properties of thematerial after testing the reverse osmosis performance. In general, themore softer and fluffier the nonwoven fabric, the drier the surface ofthe fabric will be expected.

It can be seen from the data in Table 12 that, the inventive compositesheet exhibited much better performance; this is particularly true forreverse osmosis performance. The product with alternatinggrooves/channels exhibited better diffusivity, such as suction range (inlength wise direction that is the direction of the stripes) increases byone time, which also is the main cause why the diffusion aspect ratio ofthe liquid is far more than 1. Thus, it is expected that use of thecomposite sheets as the distribution layer of absorbent articles canfully utilize the effective area of the absorption layer under thedistribution layer, minimize the investment on raw materials, and reducethe cost of production.

In addition, it can be seen by comparison of Table 12, the products ofpresent invention is fluffier (lower density) and the dry and crispproperties has been improved significantly, and the material has verygood rebound resilience, and is a kind of superior qualityquick-permeable airlaid paper. Even after the grooves/channels areembossed, the article was still fluffier (lower density) than theairlaid papers of the prior art, and both the reverse osmosisperformance and dry and crisp properties are also very good. Thisrepresents a significant improvement in comparison with the past art,and as the material has very good rebound resilience, it is a kind ofsuperior quality quick-permeable airlaid paper.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

That which is claimed:
 1. A method of preparing a composite sheet,comprising: providing a carded nonwoven fabric, the carded nonwovenfabric comprising staple fibers; depositing a first airlaid layer onto asurface of the carded nonwoven fabric to form a composite sheet, thefirst airlaid layer comprising a mixture of cellulose and non-cellulosestaple fibers; and air through bonding the composite sheet with heatedgas to cause a polymer of the non-cellulose staple fibers of the firstair laid layer to melt and fuse with adjacent fibers, whereinnon-cellulose staple fibers of the airlaid layer are bonded to eachother, the cellulose staple fibers, and to fibers of the carded nonwovenfabric layer.
 2. The method according to claim 1, wherein the step ofproviding the carded nonwoven fabric comprises preparing the cardednonwoven fabric on a carded fabric forming device disposed upstream of adevice for depositing said first airlaid layer.
 3. The method accordingto claim 1, further comprising a step of air through bonding the staplefibers of the carded nonwoven fabric prior to depositing a first airlaidlayer onto the carded nonwoven fabric.
 4. The method according to claim1, wherein the step of air through bonding the composite sheet furthercomprises air through bonding of the staple fibers of the cardednonwoven fabric to each other.
 5. The method according to claim 1,further comprising successively depositing a plurality of airlaid layersonto said first airlaid layer.
 6. The method according to claim 1,wherein the composite sheet comprises from 2 to 10 airlaid layerssuccessively deposited overlying the carded nonwoven fabric.
 7. Themethod according to claim 1, wherein the carded nonwoven fabriccomprises bicomponent staple fibers having a sheath of a first polymercomponent and a core of a second polymer component.
 8. The method ofclaim 7, wherein the first and second polymer component comprise thesame polymer.
 9. The method of claim 7, wherein the sheath comprisespolyethyelene and the core comprises polypropylene or polyethyleneterephthalate core, and mixtures thereof.
 10. The method according toclaim 1, wherein the staple fibers of the carded nonwoven fabric havinga length from about 20 to 100 millimeters (mm).
 11. The method accordingto claim 1, wherein the composite sheet material comprises one or moreairlaid layers, and the method further comprising mixing a superabsorbent polymer or super absorbent fibers with the cellulose andnon-cellulose staple fibers of at least one or more of the airlaidlayers.
 12. The method according to claim 1, wherein the carded nonwovenfabric comprises bicomponent staple fibers having a polyethyelene sheathand a polypropylene or polyethylene terephthalate core, and mixturesthereof, and the non-cellulose fibers comprise bicomponent staple fibershaving a polyethyelene sheath and a polypropylene or polyethyleneterephthalate core, and mixtures thereof.
 13. The method according toclaim 1, wherein the staple fibers of the carded nonwoven fabriccomprise bicomponent filaments having a sheath/core configuration inwhich the sheath comprises a polyethylene terepthalate (PET), and thecore comprises PET having a melting temperature higher than a meltingtemperature of the PET comprising the sheath.
 14. The method accordingto claim 1, wherein the carded nonwoven fabric comprises staple fiberscomprising a sustainable polymer, and the non-cellulose fibers of theairlaid layer comprises a sustainable polymer.
 15. The method accordingto claim 14, wherein the staple fibers of the carded nonwoven fabriccomprise bicomponent filaments a sheath/core configuration in which thesheath comprises a polylactic acid polymer (PLA), and the core comprisesPLA having a melting temperature higher than a melting temperature ofthe PLA comprising the sheath.
 16. The method according to claim 1,further comprising a step of depositing a coating layer of a polymericlatex on a surface an outermost airlaid layer, and then heating thecomposite sheet material to a temperature sufficient to cure and dry thepolymeric latex.
 17. The method according to claim 1, wherein the basisweight of the composite sheet material is from about 40 to 225 g/m², andwherein the composite sheet material is characterized by the following:a fluid acquisition time ranging from about 0.5 seconds to about 2seconds; a fluid absorption ranging from about 15 to 30 g/g; a fluidretention ranging from about 8 to 15 g/g; a fluid wicking height rangingfrom about 10 to 50 mm; and a resiliency ranging from about 30 to 60%.18. The method according to claim 1, further comprising forming aplurality of alternating ridges and channels that extend across an outersurface of the outermost airlaid layer of the composite sheet material.19. A method of preparing a composite sheet, comprising: depositing aplurality of non-cellulose staple fibers onto a collection surface toform a first nonwoven fabric layer; depositing a first airlaid layeronto a surface of the first nonwoven fabric layer, the first airlaidlayer comprising a mixture of cellulose and non-cellulose staple fibers;and bonding the staple fibers of the first nonwoven fabric layer tofibers of the first airlaid layer to form a coherent composite sheet.20. The method of claim 19, wherein the step of bonding comprises airthrough bonding the composite sheet with heated gas to cause a polymerof the non-cellulose staple fibers of the first air laid layer to meltand fuse with adjacent fibers, wherein non-cellulose staple fibers ofthe airlaid layer are bonded to each other, the cellulose staple fibers,and to the non-cellulose staple fibers.
 21. A system for preparing acomposite sheet material, the system comprising a source of a cardednonwoven fabric, the carded nonwoven fabric comprising staple fibers; acollection surface onto which the carded nonwoven fabric is deposited; afirst airlaid fabric forming head deposited downstream of the source ofthe carded nonwoven fabric, the forming head configured and arranged todeposit a stream comprising a mixture of cellulose and non-cellulosestaple fibers a surface of the carded nonwoven fabric to form acomposite sheet comprising the carded nonwoven fabric and a firstairlaid layer; an air through bonder disposed downstream of said firstairlaid fabric forming head, the air through bonder configured to exposethe composite sheet to heated gas to cause a polymer of thenon-cellulose staple fibers of the first air laid layer to melt and fusewith adjacent fibers, wherein non-cellulose staple fibers of the airlaidlayer are bonded to each other, the cellulose staple fibers, and tofibers of the carded nonwoven fabric layer.
 22. The system according toclaim 21, wherein the source of a carded nonwoven fabric comprises acarded fabric forming device disposed upstream of the first airlaidfabric forming head.
 23. The system according to claim 21, furthercomprising a plurality of airlaid fabric forming heads, wherein eachairlaid fabric forming head is configured to successively deposit anairlaid layer overlying the carded nonwoven fabric.